Fecal occult blood

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Fecal occult blood
Guaiac01.jpg
Cards and bottle used for the Hemoccult test, a type of stool guaiac test
Specialty Gastroenterology, general surgery

Fecal occult blood (FOB) refers to blood in the feces that is not visibly apparent (unlike other types of blood in stool such as melena or hematochezia). A fecal occult blood test (FOBT) checks for hidden (occult) blood in the stool (feces). [1]

Contents

The American College of Gastroenterology has recommended the abandoning of gFOBT testing as a colorectal cancer screening tool, in favor of the fecal immunochemical test (FIT). [2] The newer and recommended tests look for globin, DNA, or other blood factors including transferrin, while conventional stool guaiac tests look for heme.

Medical uses

Fecal occult blood testing (FOBT), as its name implies, aims to detect subtle blood loss in the gastrointestinal tract, anywhere from the mouth to the colon. Positive tests ("positive stool") may result from either upper gastrointestinal bleeding or lower gastrointestinal bleeding and warrant further investigation for peptic ulcers or a malignancy (such as colorectal cancer or gastric cancer). The test does not directly detect colon cancer but is often used in clinical screening for that disease. It can also be used to look for active occult blood loss in anemia [3] or when there are gastrointestinal symptoms. [4]

Colorectal cancer screening

An estimated 1–5% of large tested populations have a positive fecal occult blood test.[ citation needed ] Of those, about 2–10% have cancer, while 20–30% have adenomas. Screening methods for colon cancer depend on detecting either precancerous changes such as certain kinds of polyps or on finding early and thus more treatable cancer. The extent to which screening procedures reduce the risk of gastrointestinal cancer or deaths depends on the rate of precancerous and cancerous disease in that population. gFOBT (guaiac fecal occult blood test) and flexible sigmoidoscopy screening have each shown benefit. Other colon cancer screening tools such as iFOBT (immunochemical fecal occult blood test) or colonoscopy are also included in guidelines. [5]

In 2009, the American College of Gastroenterology (ACG) suggested that colon cancer screening modalities that are also directly preventive by removing precursor lesions should be given precedence, and prefer a colonoscopy every ten years in average-risk individuals, beginning at age 50. [2] The ACG suggests that cancer detection tests such as any type of FOB are an alternative that is less preferred, and if a colonoscopy is declined, the FIT (fecal immunochemical test, or iFOBT) should be offered instead. The 2017 US Multi-Society Task Force (MSTF)'s recommended first-tier tests are a colonoscopy every 10 years or annual FIT test. [6] If FIT is utilized, proper steps must be taken to ensure appropriate use and follow-up of abnormal FIT results. [7] FIT tests however are not that useful in picking up adenomas, even when advanced. [8]

The United States Preventive Services Task Force (USPSTF)'s 2016 recommendation, instead of emphasizing specific screening approaches, has instead chosen to highlight that there is convincing evidence that colorectal cancer screening substantially reduces deaths from the disease among adults aged 50 to 75 years and that not enough adults are using this effective preventive intervention. [9] The ACG and MSTF also included CT colonography every five years, and fecal DNA testing as considerations. All three recommendation panels recommended replacing any older low-sensitivity, guaiac-based fecal occult blood testing (gFOBT) with either newer high-sensitivity guaiac-based fecal occult blood testing (hs gFOBT) or fecal immunochemical testing (FIT). MSTF looked at six studies that compared high-sensitivity gFOBT (Hemoccult SENSA) to FIT, and concluded that there was no clear difference in overall performance between these methods.

The English National Health Service (NHS) introduced a Bowel Cancer Screening Program in 2006. [10] It is now offered to patients aged 60–74 years. In 2019 FIT was introduced as the primary screening test in England and Wales, replacing gFOBt. [11] [12] However, research carried out in the UK has suggested that the FIT threshold for further investigation is set at a point that may miss more than half of bowel cancer cases and only identifies one in four high-risk polyps. [13] [14]

The American College of Gastroenterology has recommended the abandoning of gFOBT testing as a colorectal cancer screening tool, in favor of the fecal immunochemical test. [2] Though the FIT test is preferred, even the guaiac FOB testing of average risk populations may have been sufficient to reduce the mortality associated with colon cancer by about 25%. [15] With this lower efficacy, it was not always cost-effective to screen a large population with gFOBT. [16] [17] [18] [19]

A LabCorp fecal occult blood immunoassay testing kit. Fecal occult blood immunoassay testing kit.jpg
A LabCorp fecal occult blood immunoassay testing kit.

If colon cancer is suspected in an individual (such as in someone with an unexplained anemia), fecal occult blood tests may not be clinically helpful. If a doctor suspects colon cancer, more rigorous investigation is necessary, whether or not the test is positive.[ citation needed ]

In 2006, the Australian Government introduced the National Bowel Cancer Program which has been updated several times since; targeted screening will be done of all Australians aged from 50 to 74 by 2020. Cancer Council Australia recommended that FOBT should be done every two years. People over 50 not yet eligible for the national program can arrange with their doctor for an FOBT. [20] The Canadian Cancer Society recommends that men and women aged 50 and over have an FOBT at least every two years. [21] In colon cancer screening, using only one sample of feces collected by a doctor performing a digital rectal examination is discouraged. [22]

The use of the M2-PK Test is encouraged over gFOBT for routine screening, as it may pick up tumors whether or not they are bleeding. [23] It is able to detect 80 percent of colorectal cancers and 44 percent for adenoma > 1 centimeter, while gFOBT picks up 13 to 50 percent of colorectal cancers. [23]

Other sources of bleeding

Gastrointestinal bleeding has many potential sources, and positive results usually result in further testing for the bleeding site, usually looking for lower gastrointestinal bleeding before upper gastrointestinal bleeding causes unless there are other clues. [24] Colonoscopy is usually preferred to computerized tomographic colonography. [25]

A positive test can result from upper gastrointestinal bleeding or lower gastrointestinal bleeding. The common causes are:

In the event of a positive fecal occult blood test, the next step in the workup is a form of visualization of the gastrointestinal tract by one of several means:

  1. Sigmoidoscopy, an examination of the rectum and lower colon with a lighted instrument to look for abnormalities, such as polyps.
  2. Colonoscopy, a more thorough examination of the rectum and entire colon.
  3. Virtual colonoscopy
  4. Upper gastrointestinal endoscopy. It is sometimes performed with chromoendoscopy, a method that assists the endoscopist by enhancing the visual difference between cancerous and normal tissue, by either marking the abnormally increased DNA content (toluidine blue) or failing to stain the tumor, possibly due to decreased surface glycogen on tumor cells(Lugol). [27] [28] Infrared fluorescent endoscopy[ citation needed ] and ultrasonic endoscopy[ citation needed ] can interrogate vascular abnormalities such as esophageal varices.
  5. Double-contrast barium enema: a series of x-rays of the colon and rectum.

Testing secretions for blood

The use of an FOBT for bleeding from the mouth, nose, esophagus, lungs, stomach and the initial portion of the small intestine, while the same as fecal testing, is discouraged, due to technical considerations including poorly characterized test performance characteristics such as sensitivity, specificity, and analytical interference. [29] However, chemical confirmation that coloration is due to blood rather than coffee, beets, medications, or food additives can be of significant clinical assistance.

Marathon runners

Gastrointestinal (GI) complaints and low-intensity GI bleeding frequently occur in marathon runners. [30] Strenuous exercise, particularly in elite athlete runners and less frequently in other exercise activities, can cause acute incapacitating gastrointestinal symptoms including heartburn, nausea, vomiting, abdominal pain, diarrhea and gastrointestinal bleeding. [31] Approximately one third of endurance runners experience transient but exercise-limiting symptoms, and repetitive gastrointestinal bleeding occasionally causes iron deficiency and anaemia. [32] [33] Runners can sometimes experience significant symptoms including hematemesis. [34] Exercise is associated with extensive changes in gastrointestinal (GI) tract physiology, including diversion of blood flow from the GI tract to muscles and lungs, decreased GI absorption and small intestinal motility, increased colonic transit, neuroimmunoendocrine changes in hormones and peptides such as vasoactive intestinal peptide, secretin and peptide-histidine-methionine. [35] Substantial changes occur in stress hormones including cortisol, in circulating concentrations and metabolic behavior of various leucocytes, and in immunoglobulin levels and major histocompatibility complex expression. [36] Symptoms can be exacerbated by dehydration or by pre-exercise ingestion of certain foods and hypertonic liquids, and lessened by adequate training. [35]

Ingestion of 800 mg of cimetidine two hours before running a marathon did not significantly affect the frequency of gastrointestinal symptoms or occult gastrointestinal bleeding. [37] Conversely, 800 mg of cimetidine 1 hr before the start and again at 50 miles of a 100-mile running race substantially decreased GI symptoms and post-race guaiac test positivity but did not affect race performance. [38]

Methodology

There are four methods in clinical use to test for occult blood in feces. These look at different properties, such as antibodies, heme, globin, or porphyrins in blood, or at DNA from cellular material such as from lesions of the intestinal mucosa.

A positive traditional guaiac fecal occult blood test Positive fecal occult blood test.jpg
A positive traditional guaiac fecal occult blood test

Additional methods of looking for occult blood are being explored, including transferrin dipstick [48] and stool cytology. [49]

Test performance

Reference standards

The estimates for test performance characteristics are based on comparison with a variety of reference methods including 51-chromium studies,[ citation needed ] analytical recovery studies in spiked stool samples, analytical recovery after ingestion of autologous blood, rarer studies of carefully quantified blood instilled at bowel surgery [ citation needed ], as well as other research approaches.[ citation needed ] Additionally, clinical studies look at a variety of additional factors.

Gastrointestinal blood loss

In healthy people about 0.5 to 1.5 ml of blood escapes blood vessels into the stool each day. [50] [51] [52] Significant amounts of blood can be lost without producing visible blood in the stool, estimated as 200 ml in the stomach, [53] 100 ml in the duodenum, and lesser amounts in the lower intestine. Tests for occult blood identify lesser blood loss.

Clinical sensitivity and specificity

Fecal immunochemical testing (FIT) can identify as little as 0.3 ml of daily blood in the stool; yet this test threshold does not cause undue false positives from normal upper intestinal blood leakage because it does not detect occult blood from the stomach and upper small intestine. Thus, the FIT test is much more specific for bleeding from the colon or lower gastrointestinal tract than alternatives. [54] The detection rate of the test decreases if the time from sample collection to laboratory processing is delayed; processing the sample in under five days from collection is recommended. [55] It does not appear to be affected by aspirin, anticoagulants, or nonsteroidal anti-inflammatory drugs. [56]

Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending on the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood loss of about 10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can pick up lesser amounts, requires at least 2 ml to become positive. The sensitivity of a single-stool guaiac test to pick up bleeding has been quoted at 10 to 30%, but if a standard three tests are done as recommended the sensitivity rises to 92%. [57] Reduced patient compliance with the collection of three samples hampers the usefulness of this test. Further discussion of sensitivity and specificity issues that relate particularly to the guaiac method is found in the stool guaiac test article.

Fecal porphyrin quantification by HemoQuant can yield a false positive result due to exogenous blood and various porphyrins. HemoQuant is the most sensitive test for upper gastrointestinal bleeding and therefore may be most appropriate fecal occult blood test to use in the evaluation of iron deficiency. [58] It is advisable to stop ingesting red meat and aspirin for three days prior to specimen collection. [59] False positives can occur with myoglobin, catalase, or protohemes [60] and in certain types of porphyria.[ citation needed ]

Fecal DNA tests as of 2008 had not been studied enough to support widespread use. [61]

Regulation

Safety regulations from US accreditor the Joint Commission may have unintentionally decreased digital rectal examination and FOBT in hospital settings such as Emergency Departments. [62] [63]

Related Research Articles

<span class="mw-page-title-main">Large intestine</span> Last part of the digestive system in vertebrates

The large intestine, also known as the large bowel, is the last part of the gastrointestinal tract and of the digestive system in tetrapods. Water is absorbed here and the remaining waste material is stored in the rectum as feces before being removed by defecation. The colon is the longest portion of the large intestine, and the terms are often used interchangeably but most sources define the large intestine as the combination of the cecum, colon, rectum, and anal canal. Some other sources exclude the anal canal.

<span class="mw-page-title-main">Constipation</span> Bowel dysfunction

Constipation is a bowel dysfunction that makes bowel movements infrequent or hard to pass. The stool is often hard and dry. Other symptoms may include abdominal pain, bloating, and feeling as if one has not completely passed the bowel movement. Complications from constipation may include hemorrhoids, anal fissure or fecal impaction. The normal frequency of bowel movements in adults is between three per day and three per week. Babies often have three to four bowel movements per day while young children typically have two to three per day.

<span class="mw-page-title-main">Colorectal cancer</span> Cancer of the colon or rectum

Colorectal cancer (CRC), also known as bowel cancer, colon cancer, or rectal cancer, is the development of cancer from the colon or rectum. Signs and symptoms may include blood in the stool, a change in bowel movements, weight loss, and fatigue. Most colorectal cancers are due to old age and lifestyle factors, with only a small number of cases due to underlying genetic disorders. Risk factors include diet, obesity, smoking, and lack of physical activity. Dietary factors that increase the risk include red meat, processed meat, and alcohol. Another risk factor is inflammatory bowel disease, which includes Crohn's disease and ulcerative colitis. Some of the inherited genetic disorders that can cause colorectal cancer include familial adenomatous polyposis and hereditary non-polyposis colon cancer; however, these represent less than 5% of cases. It typically starts as a benign tumor, often in the form of a polyp, which over time becomes cancerous.

<span class="mw-page-title-main">Colonoscopy</span> Examination of the bowel

Colonoscopy or coloscopy is a medical procedure involving the endoscopic examination of the large bowel (colon) and the distal portion of the small bowel. This examination is performed using either a CCD camera or a fiber optic camera, which is mounted on a flexible tube and passed through the anus.

<span class="mw-page-title-main">Rectal examination</span> Medical assessment or diagnostic procedure

Digital rectal examination (DRE), also known as a prostate exam, is an internal examination of the rectum performed by a healthcare provider.

<span class="mw-page-title-main">Angiodysplasia</span> Medical condition

In medicine (gastroenterology), angiodysplasia is a small vascular malformation of the gut. It is a common cause of otherwise unexplained gastrointestinal bleeding and anemia. Lesions are often multiple, and frequently involve the cecum or ascending colon, although they can occur at other places. Treatment may be with colonoscopic interventions, angiography and embolization, medication, or occasionally surgery.

<span class="mw-page-title-main">Diverticulosis</span> Condition of the wall of the intestine

Diverticulosis is the condition of having multiple pouches (diverticula) in the colon that are not inflamed. These are outpockets of the colonic mucosa and submucosa through weaknesses of muscle layers in the colon wall. Diverticula do not cause symptoms in most people. Diverticular disease occurs when diverticula become clinically inflamed, a condition known as diverticulitis.

<span class="mw-page-title-main">Gastrointestinal bleeding</span> Medical condition

Gastrointestinal bleeding, also called gastrointestinal hemorrhage (GIB), is all forms of bleeding in the gastrointestinal tract, from the mouth to the rectum. When there is significant blood loss over a short time, symptoms may include vomiting red blood, vomiting black blood, bloody stool, or black stool. Small amounts of bleeding over a long time may cause iron-deficiency anemia resulting in feeling tired or heart-related chest pain. Other symptoms may include abdominal pain, shortness of breath, pale skin, or passing out. Sometimes in those with small amounts of bleeding no symptoms may be present.

<span class="mw-page-title-main">Stool test</span> Medical examination of fecal matter

A stool test is a medical diagnostic technique that involves the collection and analysis of fecal matter. Microbial analysis (culturing), microscopy and chemical tests are among the tests performed on stool samples.

<span class="mw-page-title-main">Virtual colonoscopy</span> Medical imaging of the colon

Virtual colonoscopy is the use of CT scanning or magnetic resonance imaging (MRI) to produce two- and three-dimensional images of the colon, from the lowest part, the rectum, to the lower end of the small intestine, and to display the images on an electronic display device. The procedure is used to screen for colon cancer and polyps, and may detect diverticulosis. A virtual colonoscopy can provide 3D reconstructed endoluminal views of the bowel. VC provides a secondary benefit of revealing diseases or abnormalities outside the colon.

<span class="mw-page-title-main">Blood in stool</span> Medical condition

Blood in stool or rectal bleeding looks different depending on how early it enters the digestive tract—and thus how much digestive action it has been exposed to—and how much there is. The term can refer either to melena, with a black appearance, typically originating from upper gastrointestinal bleeding; or to hematochezia, with a red color, typically originating from lower gastrointestinal bleeding. Evaluation of the blood found in stool depends on its characteristics, in terms of color, quantity and other features, which can point to its source, however, more serious conditions can present with a mixed picture, or with the form of bleeding that is found in another section of the tract. The term "blood in stool" is usually only used to describe visible blood, and not fecal occult blood, which is found only after physical examination and chemical laboratory testing.

Rectal bleeding refers to bleeding in the rectum. There are many causes of rectal hemorrhage, including inflamed hemorrhoids, rectal varices, proctitis, stercoral ulcers and infections. Diagnosis is usually made by proctoscopy, which is an endoscopic test.

<span class="mw-page-title-main">Lower gastrointestinal bleeding</span> Medical condition

Lower gastrointestinal bleeding, commonly abbreviated LGIB, is any form of gastrointestinal bleeding in the lower gastrointestinal tract. LGIB is a common reason for seeking medical attention at a hospital's emergency department. LGIB accounts for 30–40% of all gastrointestinal bleeding and is less common than upper gastrointestinal bleeding (UGIB). It is estimated that UGIB accounts for 100–200 per 100,000 cases versus 20–27 per 100,000 cases for LGIB. Approximately 85% of lower gastrointestinal bleeding involves the colon, 10% are from bleeds that are actually upper gastrointestinal bleeds, and 3–5% involve the small intestine.

Tumor M2-PK is a synonym for the dimeric form of the pyruvate kinase isoenzyme type M2 (PKM2), a key enzyme within tumor metabolism. Tumor M2-PK can be elevated in many tumor types, rather than being an organ-specific tumor marker such as PSA. Increased stool (fecal) levels are being investigated as a method of screening for colorectal tumors, and EDTA plasma levels are undergoing testing for possible application in the follow-up of various cancers.

<span class="mw-page-title-main">Stool guaiac test</span> Test for the presence for occult blood

The stool guaiac test or guaiac fecal occult blood test (gFOBT) is one of several methods that detects the presence of fecal occult blood. The test involves placing a fecal sample on guaiac paper and applying hydrogen peroxide which, in the presence of blood, yields a blue reaction product within seconds.

<span class="mw-page-title-main">Human feces</span> Metabolic waste of the human digestive system

Human feces are the solid or semisolid remains of food that could not be digested or absorbed in the small intestine of humans, but has been further broken down by bacteria in the large intestine. It also contains bacteria and a relatively small amount of metabolic waste products such as bacterially altered bilirubin, and the dead epithelial cells from the lining of the gut. It is discharged through the anus during a process called defecation.

<span class="mw-page-title-main">M2-PK Test</span> Screening for colorectal cancers and polyps

The M2-PK Test is a non-invasive screening method for the early detection of colorectal cancers and polyps which are known to be the precursors of colorectal cancer. The M2-PK Test which is used for stool analysis is available either as fully quantitative ELISA Test or as a rapid test that can be performed by any general practitioner without the need of a laboratory or any additional equipment.

A rectovaginal examination is a type of gynecological examination used to supplement a pelvic examination. In the rectovaginal examination, a doctor or other health care provider places one finger in the vagina and another in the rectum to assess the rectovaginal septum. The examiner will look for any scarring or masses that may indicate cancer or another disease. Typically, a rectovaginal examination is performed to assess pelvic pain, rectal symptoms, or a pelvic mass. It can also provide a sample for fecal occult blood testing.

<span class="mw-page-title-main">Fecal immunochemical test</span> Diagnostic test for colorectal cancer

Fecal Immunochemical Test (FIT) is a diagnostic technique that examines stool samples for traces of non-visible blood, which could potentially indicate conditions including bowel cancer. Symptoms which could be caused by bowel cancer and suggest a FIT include a change in bowel habit, anaemia, unexplained weight loss, and abdominal pain. By using a random forest classification model, sensitivity can be increased.

<span class="mw-page-title-main">Serrated polyposis syndrome</span> Medical condition

Serrated polyposis syndrome (SPS), previously known as hyperplastic polyposis syndrome, is a disorder characterized by the appearance of serrated polyps in the colon. While serrated polyposis syndrome does not cause symptoms, the condition is associated with a higher risk of colorectal cancer (CRC). The lifelong risk of CRC is between 25 and 40%. SPS is the most common polyposis syndrome affecting the colon, but is under recognized due to a lack of systemic long term monitoring. Diagnosis requires colonoscopy, and is defined by the presence of either of two criteria: ≥5 serrated lesions/polyps proximal to the rectum, or >20 serrated lesions/polyps of any size distributed throughout the colon with 5 proximal to the rectum.

References

  1. ↑ Beg M, Singh M, Saraswat MK, Rewari BB (2002). "Occult Gastrointestinal Bleeding: Detection, Interpretation, and Evaluation" (PDF). JIACM. 3 (2): 153–58. Archived (PDF) from the original on 2010-11-22.
  2. 1 2 3 4 5 Rex DK, Johnson DA, Anderson JC, Schoenfeld PS, Burke CA, Inadomi JM (March 2009). "American College of Gastroenterology guidelines for colorectal cancer screening 2009 [corrected]". The American Journal of Gastroenterology. 104 (3): 739–750. doi: 10.1038/ajg.2009.104 . PMID   19240699. S2CID   295873.
  3. ↑ Harewood GC, Ahlquist DA (2000). "Fecal occult blood testing for iron deficiency: a reappraisal". Digestive Diseases. 18 (2): 75–82. doi:10.1159/000016968. PMID   11060470. S2CID   29966595.
  4. ↑ Bardhan PK, Beltinger J, Beltinger RW, Hossain A, Mahalanabis D, Gyr K (January 2000). "Screening of patients with acute infectious diarrhoea: evaluation of clinical features, faecal microscopy, and faecal occult blood testing". Scandinavian Journal of Gastroenterology. 35 (1): 54–60. doi:10.1080/003655200750024533. PMID   10672835. S2CID   218910557.
  5. ↑ Robertson DJ, Lee JK, Boland CR, Dominitz JA, Giardiello FM, Johnson DA, et al. (April 2017). "Recommendations on Fecal Immunochemical Testing to Screen for Colorectal Neoplasia: A Consensus Statement by the US Multi-Society Task Force on Colorectal Cancer". Gastroenterology. 152 (5): 1217–1237.e3. doi: 10.1053/j.gastro.2016.08.053 . PMID   27769517.
  6. ↑ Rex DK, Boland CR, Dominitz JA, Giardiello FM, Johnson DA, Kaltenbach T, et al. (July 2017). "Colorectal Cancer Screening: Recommendations for Physicians and Patients From the U.S. Multi-Society Task Force on Colorectal Cancer". Gastroenterology. Elsevier BV. 153 (1): 307–323. doi:10.1053/j.gastro.2017.05.013. PMID   28600072.
  7. ↑ Cusumano VT, May FP (June 2020). "Making FIT Count: Maximizing Appropriate Use of the Fecal Immunochemical Test for Colorectal Cancer Screening Programs". Journal of General Internal Medicine. JGIM. 35 (6): 1870–1874. doi:10.1007/s11606-020-05728-y. PMC   7280423 . PMID   32128688.
  8. ↑ Imperiale TF, Gruber RN, Stump TE, Emmett TW, Monahan PO (March 2019). "Performance Characteristics of Fecal Immunochemical Tests for Colorectal Cancer and Advanced Adenomatous Polyps: A Systematic Review and Meta-analysis". Annals of Internal Medicine. 170 (5): 319–329. doi:10.7326/M18-2390. hdl: 1805/21570 . PMID   30802902. S2CID   67876943.
  9. ↑ "Final Recommendation Statement: Colorectal Cancer: Screening". U.S. Preventive Services Task Force. June 2016. Retrieved 7 April 2019.
  10. ↑ Koo S, Neilson LJ, Von Wagner C, Rees CJ (2017-12-04). "The NHS Bowel Cancer Screening Program: current perspectives on strategies for improvement". Risk Management and Healthcare Policy. 10: 177–187. doi: 10.2147/RMHP.S109116 . PMC   5720037 . PMID   29270036.
  11. ↑ "CKS is only available in the UK". NICE. Retrieved 2022-08-05.
  12. ↑ "Bowel cancer screening". nhs.uk. 2017-10-20. Retrieved 2022-08-05.
  13. ↑ "New pathways could improve bowel cancer screening". NIHR Evidence. 2021-09-13. doi:10.3310/alert_47581. S2CID   239113610 . Retrieved 2022-08-05.
  14. ↑ Li SJ, Sharples LD, Benton SC, Blyuss O, Mathews C, Sasieni P, Duffy SW (September 2021). "Faecal immunochemical testing in bowel cancer screening: Estimating outcomes for different diagnostic policies". Journal of Medical Screening. 28 (3): 277–285. doi:10.1177/0969141320980501. PMC   8366184 . PMID   33342370.
  15. ↑ Bretthauer M (August 2010). "Evidence for colorectal cancer screening". Best Practice & Research. Clinical Gastroenterology. 24 (4): 417–425. doi:10.1016/j.bpg.2010.06.005. PMID   20833346.
  16. ↑ Mandel JS, Bond JH, Church TR, Snover DC, Bradley GM, Schuman LM, Ederer F (May 1993). "Reducing mortality from colorectal cancer by screening for fecal occult blood. Minnesota Colon Cancer Control Study". The New England Journal of Medicine. 328 (19): 1365–1371. doi: 10.1056/NEJM199305133281901 . PMID   8474513. S2CID   6756273.
  17. ↑ Hardcastle JD, Chamberlain JO, Robinson MH, Moss SM, Amar SS, Balfour TW, et al. (November 1996). "Randomised controlled trial of faecal-occult-blood screening for colorectal cancer". Lancet. 348 (9040): 1472–1477. doi:10.1016/S0140-6736(96)03386-7. PMID   8942775. S2CID   11395104.
  18. ↑ Kronborg O, Fenger C, Olsen J, Jørgensen OD, Søndergaard O (November 1996). "Randomised study of screening for colorectal cancer with faecal-occult-blood test". Lancet. 348 (9040): 1467–1471. doi:10.1016/S0140-6736(96)03430-7. PMID   8942774. S2CID   37515050.
  19. ↑ Kewenter J, Brevinge H, Engarås B, Haglind E, Ahrén C (May 1994). "Results of screening, rescreening, and follow-up in a prospective randomized study for detection of colorectal cancer by fecal occult blood testing. Results for 68,308 subjects". Scandinavian Journal of Gastroenterology. 29 (5): 468–473. doi:10.3109/00365529409096840. PMID   8036464.
  20. ↑ "Bowel cancer screening program". Cancer Council Australia. 19 June 2018. Retrieved 11 December 2018.
  21. ↑ "Screening for colorectal cancer". Canadian Cancer Society. 2018. Retrieved 11 December 2018.
  22. 1 2 Collins JF, Lieberman DA, Durbin TE, Weiss DG (January 2005). "Accuracy of screening for fecal occult blood on a single stool sample obtained by digital rectal examination: a comparison with recommended sampling practice". Annals of Internal Medicine. 142 (2): 81–85. CiteSeerX   10.1.1.580.829 . doi:10.7326/0003-4819-142-2-200501180-00006. PMID   15657155. S2CID   29833684.
  23. 1 2 Tonus C, Sellinger M, Koss K, Neupert G (August 2012). "Faecal pyruvate kinase isoenzyme type M2 for colorectal cancer screening: a meta-analysis". World Journal of Gastroenterology. 18 (30): 4004–4011. doi: 10.3748/wjg.v18.i30.4004 . PMC   3419997 . PMID   22912551.
  24. ↑ Rockey DC (December 2005). "Occult gastrointestinal bleeding". Gastroenterology Clinics of North America. 34 (4): 699–718. doi:10.1016/j.gtc.2005.08.010. PMID   16303578.
  25. ↑ Walleser S, Griffiths A, Lord SJ, Howard K, Solomon MJ, Gebski V (December 2007). "What is the value of computered tomography colonography in patients screening positive for fecal occult blood? A systematic review and economic evaluation". Clinical Gastroenterology and Hepatology. 5 (12): 1439–46, quiz 1368. doi:10.1016/j.cgh.2007.09.003. PMID   18054752.
  26. 1 2 3 Bevan R, Lee TJ, Nickerson C, Rubin G, Rees CJ (June 2014). "Non-neoplastic findings at colonoscopy after positive faecal occult blood testing: data from the English Bowel Cancer Screening Programme". Journal of Medical Screening. 21 (2): 89–94. doi:10.1177/0969141314528889. PMID   24644029. S2CID   40548811.
  27. ↑ Endo M, Sakakibara N, Suzuki H (1972). "Observation of esophageal lesions with the use of endoscopic dyes". Progress of Digestive Endoscopy. 1: 34.
  28. ↑ Endo M, Takeshita K, Yoshida M (September 1986). "How can we diagnose the early stage of esophageal cancer? Endoscopic diagnosis". Endoscopy. 18 (Suppl 3): 11–18. doi:10.1055/s-2007-1018435. PMID   2428607. S2CID   34757654.
  29. ↑ Mathews B, Ratcliffe T, Sehgal R, Abraham J, Monash B (July 2017). "Fecal Occult Blood Testing in Hospitalized Patients with Upper Gastrointestinal Bleeding". Journal of Hospital Medicine. 12 (7): 567–569. doi: 10.12788/jhm.2773 . PMID   28699947.
  30. ↑ Halvorsen FA, Lyng J, Ritland S (May 1986). "Gastrointestinal bleeding in marathon runners". Scandinavian Journal of Gastroenterology. 21 (4): 493–497. doi:10.3109/00365528609015168. PMID   3487825.
  31. ↑ de Oliveira EP, Burini RC (September 2009). "The impact of physical exercise on the gastrointestinal tract". Current Opinion in Clinical Nutrition and Metabolic Care. 12 (5): 533–538. doi:10.1097/MCO.0b013e32832e6776. PMID   19535976. S2CID   21085826.
  32. ↑ Peters HP, De Vries WR, Vanberge-Henegouwen GP, Akkermans LM (March 2001). "Potential benefits and hazards of physical activity and exercise on the gastrointestinal tract". Gut. 48 (3): 435–439. doi:10.1136/gut.48.3.435. PMC   1760153 . PMID   11171839.
  33. ↑ Toy KA, Conran RM (2022-01-01). "Educational Case: Diverticulosis". Academic Pathology. 9 (1): 100014. doi:10.1016/j.acpath.2022.100014. PMC   9115725 . PMID   35600744.
  34. ↑ Weaver LT (1984). "Do some marathon runners bleed into the gut? (letter response to a previous article)". BMJ. 288 (6410): 65. doi:10.1136/bmj.288.6410.65-b. PMC   1444190 .
  35. 1 2 Brouns F, Beckers E (April 1993). "Is the gut an athletic organ? Digestion, absorption and exercise". Sports Medicine. 15 (4): 242–257. doi:10.2165/00007256-199315040-00003. PMID   8460288. S2CID   26732943.
  36. ↑ Venkatraman JT, Pendergast DR (2002). "Effect of dietary intake on immune function in athletes". Sports Medicine. 32 (5): 323–337. CiteSeerX   10.1.1.556.6186 . doi:10.2165/00007256-200232050-00004. PMID   11929359. S2CID   25330480.
  37. ↑ Moses FM, Baska RS, Peura DA, Deuster PA (October 1991). "Effect of cimetidine on marathon-associated gastrointestinal symptoms and bleeding". Digestive Diseases and Sciences. 36 (10): 1390–1394. doi:10.1007/BF01296804. PMID   1914760. S2CID   8264981.
  38. ↑ Baska RS, Moses FM, Deuster PA (August 1990). "Cimetidine reduces running-associated gastrointestinal bleeding. A prospective observation". Digestive Diseases and Sciences. 35 (8): 956–960. doi:10.1007/BF01537243. PMID   2384041. S2CID   1978110.
  39. 1 2 Quintero E (October 2009). "[Chemical or immunological tests for the detection of fecal occult blood in colorectal cancer screening?]". Gastroenterologia y Hepatologia (in Spanish). 32 (8): 565–576. doi:10.1016/j.gastrohep.2009.01.179. PMID   19577340.
  40. ↑ Colorectal Cancer http://patients.gi.org/topics/colorectal-cancer Archived 2019-04-19 at the Wayback Machine
  41. ↑ Young GP, Cole SR (March 2009). "Which fecal occult blood test is best to screen for colorectal cancer?". Nature Clinical Practice. Gastroenterology & Hepatology. 6 (3): 140–141. doi:10.1038/ncpgasthep1358. PMID   19174764. S2CID   26481612.
  42. ↑ Berchi C, Bouvier V, Réaud JM, Launoy G (March 2004). "Cost-effectiveness analysis of two strategies for mass screening for colorectal cancer in France". Health Economics. 13 (3): 227–238. doi: 10.1002/hec.819 . PMID   14981648.
  43. ↑ Kuriyama M, Kato J, Takemoto K, Hiraoka S, Okada H, Yamamoto K (March 2010). "Prediction of flare-ups of ulcerative colitis using quantitative immunochemical fecal occult blood test". World Journal of Gastroenterology. 16 (9): 1110–1114. doi: 10.3748/wjg.v16.i9.1110 . PMC   2835788 . PMID   20205282.
  44. ↑ Span P (2021-01-11). "A Colonoscopy Alternative Comes Home". The New York Times. ISSN   0362-4331 . Retrieved 2021-01-12.
  45. ↑ Rockey DC (July 1999). "Occult gastrointestinal bleeding". The New England Journal of Medicine. 341 (1): 38–46. doi:10.1056/NEJM199907013410107. PMID   10387941.
  46. ↑ "Diagnostic Tests — Fecal Occult Blood Test". Archived from the original on 2007-07-07. Retrieved 2007-07-18.
  47. ↑ "Fecal Occult Blood Test (FOBT)". WebMD. Retrieved 2007-07-18.
  48. ↑ Sheng JQ, Li SR, Wu ZT, Xia CH, Wu X, Chen J, Rao J (August 2009). "Transferrin dipstick as a potential novel test for colon cancer screening: a comparative study with immuno fecal occult blood test". Cancer Epidemiology, Biomarkers & Prevention. 18 (8): 2182–2185. doi: 10.1158/1055-9965.EPI-09-0309 . PMID   19661074.
  49. ↑ Sheng JQ, Li SR, Su H, Li JS, Sun ZQ, Wu ZT, et al. (June 2010). "Fecal cytology in conjunction with immunofecal occult blood test for colorectal cancer screening". Analytical and Quantitative Cytology and Histology. 32 (3): 131–135. PMID   20701065.
  50. ↑ Ahlquist DA, McGill DB, Schwartz S, Taylor WF, Owen RA (May 1985). "Fecal blood levels in health and disease. A study using HemoQuant". The New England Journal of Medicine. 312 (22): 1422–1428. doi:10.1056/NEJM198505303122204. PMID   3873009.
  51. ↑ Dybdahl JH, Daae LN, Larsen S (1981). "Occult faecal blood loss determined by chemical tests and a 51 Cr method". Scandinavian Journal of Gastroenterology. 16 (2): 245–252. doi:10.3109/00365528109181963. PMID   7313535.
  52. ↑ St John DJ, Young GP (April 1978). "Evaluation of radiochromium blood loss studies in unexplained iron-deficiency anaemia". Australian and New Zealand Journal of Medicine. 8 (2): 121–126. doi:10.1111/j.1445-5994.1978.tb04496.x. PMID   307949.
  53. ↑ Schiff L, Stevens RJ, Shapiro N, et al. Observations on the oral administration of citrate blood in man. Am J Med Sci 1942; 203: 409.
  54. ↑ "What Does a Positive Fecal Occult Blood Test Mean? – B01" . Retrieved 2007-07-18.
  55. ↑ van Rossum LG, van Rijn AF, van Oijen MG, Fockens P, Laheij RJ, Verbeek AL, et al. (August 2009). "False negative fecal occult blood tests due to delayed sample return in colorectal cancer screening". International Journal of Cancer. 125 (4): 746–750. doi: 10.1002/ijc.24458 . PMID   19408302.
  56. ↑ Nieuwenburg SA, Vuik FE, Kruip MJ, Kuipers EJ, Spaander MC (May 2019). "Effect of anticoagulants and NSAIDs on accuracy of faecal immunochemical tests (FITs) in colorectal cancer screening: a systematic review and meta-analysis". Gut. 68 (5): 866–872. doi:10.1136/gutjnl-2018-316344. PMID   29871970. S2CID   46949140.
  57. ↑ "Screening average risk patients for colorectal cancer – B01" . Retrieved 2007-10-25.
  58. ↑ Harewood GC, McConnell JP, Harrington JJ, Mahoney DW, Ahlquist DA (January 2002). "Detection of occult upper gastrointestinal tract bleeding: performance differences in fecal occult blood tests". Mayo Clinic Proceedings. 77 (1): 23–28. doi:10.4065/77.1.23. PMID   11794453.
  59. ↑ "Test ID: HQ HemoQuant, Feces". Mayo Clinic: Mayo Clinical Laboratories.
  60. ↑ Schwartz S, Dahl J, Ellefson M, Ahlquist D (December 1983). "The "HemoQuant" test: a specific and quantitative determination of heme (hemoglobin) in feces and other materials". Clinical Chemistry. 29 (12): 2061–2067. doi: 10.1093/clinchem/29.12.2061 . PMID   6640900.
  61. ↑ Whitlock EP, Lin J, Liles E, Beil T, Fu R, O'Connor E, Thompson RN, Cardenas T (2008). "Screening for Colorectal Cancer: An Updated Systematic Review". Agency for Healthcare Research and Quality. PMID   20722162. Report No.: 08-05-05124-EF-1.
  62. ↑ Adams BD, McHugh KJ, Bryson SA, Dabulewicz J (February 2008). "The law of unintended consequences: The Joint Commission regulations and the digital rectal examination". Annals of Emergency Medicine. 51 (2): 197–201, 201.e1. doi:10.1016/j.annemergmed.2007.07.022. PMID   17961818.
  63. ↑ Cleveland NJ, Yaron M, Ginde AA (August 2010). "The effect of removal of point-of-care fecal occult blood testing on performance of digital rectal examinations in the emergency department". Annals of Emergency Medicine. 56 (2): 135–141. doi: 10.1016/j.annemergmed.2009.12.021 . PMID   20060198.
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