Intestinal pseudo-obstruction | |
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Pronunciation |
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Specialty | Gastroenterology |
Symptoms | Abdominal pain, nausea, distention, vomiting, dysphagia, and constipation |
Complications | Intestinal failure, malabsorption, nutrient deficiencies, small intestinal bacterial overgrowth |
Duration | Varies according to etiology of disease. < 6 months is considered acute |
Causes | Idiopathic, Kawasaki disease, Parkinson's disease, Chagas disease, Hirschsprung's disease, intestinal hypogangliosis, collagen vascular disease, mitochondrial disease, endocrine disorders, medication side effects |
Diagnostic method | Signs and symptoms consistent with a mechanical intestinal obstruction with no identifying lesion. |
Differential diagnosis | Intestinal obstruction, Crohn's disease, ovarian torsion, ovarian cyst, neoplasm, infection (parasitic) |
Treatment | Aimed at management of complications (e.g. nutrition, hydration, pain relief). |
Prognosis | 10–25% mortality rate in chronic cases |
Frequency | Unknown |
Intestinal pseudo-obstruction (IPO) is a clinical syndrome caused by severe impairment in the ability of the intestines to push food through. It is characterized by the signs and symptoms of intestinal obstruction without any lesion in the intestinal lumen. [1] Clinical features mimic those seen with mechanical intestinal obstructions and can include abdominal pain, nausea, abdominal distension, vomiting, dysphagia and constipation [2] [3] depending upon the part of the gastrointestinal tract involved.
It is a difficult condition to diagnose, requiring exclusion of any other mechanical cause of obstruction. [4] Many patients are diagnosed late in the course of disease after additional symptoms are seen. Mortality is also difficult to accurately determine. One retrospective study estimated mortality to be between 10 and 25% for chronic intestinal pseudo-obstruction (CIPO) and to vary greatly depending on the etiology of the condition. [5] When present for less than six months, it is diagnosed as acute IPO [6] or Ogilvie syndrome. [4] Longer than this is considered chronic. [7] Owing to the difficulty of diagnosis, few studies are available which have attempted to estimate its prevalence. [8]
The condition can begin at any age. Most studies describing CIPO are in pediatric populations. [9] [10] [4] It can be a primary condition (idiopathic or inherited) or caused by another disease (secondary). [11] It can be a result of myriad of etiologies including infectious, parasitic, autoimmune, genetic, congenital, neurologic, toxic, endocrinological, or anatomical pathology.
Treatment targets nutritional support, improving intestinal motility, and minimizing surgical intervention. [4] Bacterial overgrowth of the small intestine can occur in chronic cases – presenting as malabsorption, diarrhea, and nutrient deficiencies [12] – which may require the use of antibiotics.
Clinical features of IPO can include abdominal pain, nausea, abdominal distension, vomiting, dysphagia, and constipation. Symptoms depend on the portion of the gastrointestinal tract involved [2] and the duration of symptoms. Symptoms may occur intermittently and over a prolonged period of time. It is not unusual for patients to present several times owing to the nonspecific nature of the symptoms. [4] Conditions and onset will vary if the disease is primary vs secondary and the underlying disease (if a secondary manifestation) and its management.
Symptoms indicative of advanced disease and possible intestinal failure include diarrhea, loss of appetite, sepsis, bloating, fatigue, signs of low volume status, and malabsorption including nutritional deficiencies and foul-smelling stools. [13] [14]
In primary CIPO (the majority of chronic cases) the condition results from disruption of the intestine's ability to move food. These can be broadly classified as myopathic (affecting the smooth muscle), mesenchymopathic (affecting the interstitial cells of Cajal), or neuropathic (of the nervous system) of the gastrointestinal tract. [15]
In some cases there appears to be a genetic association. [16] One form has been associated with DXYS154, some associated with defective ACTG2 gene [17]
Secondary chronic intestinal pseudo-obstruction can occur as a consequence of a number of other conditions including:
The term may be used synonymously with enteric neuropathy if a neurological cause is suspected.
The symptoms of IPO are nonspecific. It is not unusual for patients to present repeatedly and to undergo numerous tests. [4] Mechanical causes of intestinal obstruction must be excluded to reach a diagnosis of pseudo-obstruction. Attempts must also be made to determine whether the IPO is the result of a primary or secondary condition. [15] A diagnostic work-up may include: [14]
Pseudo-obstruction syndromes are classified as acute or chronic based on their clinical appearance. Acute colonic pseudo-obstruction (ACPO; sometimes known as Ogilvie syndrome) causes the colon to become grossly dilated; if not decompressed, the individual risks perforation, peritonitis, and death. Chronic intestinal pseudo-obstruction is a chronic disorder. [24]
Treatment for IPO (acute or chronic) is aimed at removing the disease process and/or managing the complications present. Focus is placed on management of pain, gastrointestinal symptoms, nutritional deficiencies, fluid status, infection control, and improving quality of life. When CIPO is secondary to another disease, treatment is addressed towards the underlying condition. Surgery is sometimes required in severe cases of CIPO.
Prucalopride, [25] [26] pyridostigmine, [11] metoclopramide, cisapride, erythromycin, [9] and octreotide [9] [27] [28] are medications that aim to enhance intestinal motility.
Intestinal stasis, which may lead to bacterial overgrowth and subsequently, diarrhea or malabsorption, is treated with antibiotics.
Nutritional deficiencies are treated by encouraging patients to avoid foods that increase distention and are difficult to digest (e.g. those high in fat and fibre), consuming small frequent meals (5–6 per day), focusing on liquids and soft food. Reducing intake of poorly absorbed sugar alcohols may be of benefit. Referral to an accredited dietitian is recommended. If dietary changes are unsuccessful in meeting nutritional requirements and energy needs, enteral nutrition is used. Many patients eventually require parenteral nutrition. [15]
Total parenteral nutrition (TPN) is a form of long-term nutritional treatment reserved for patients that have severe pseudo-obstruction. TPN dependent patients require frequent checkups to monitor catheter function, check liver enzyme levels, and evaluate for signs of blood infections. TPN format is typically changed depending on loss/gain of weight and bloodwork results, and is specially formulated to meet each individual patient's needs. [29]
Intestinal decompression by tube placement in a small stoma can also be used to reduce distension and pressure within the gut. The stoma may be a gastrostomy, jejunostomy, ileostomy, or cecostomy. These may be used for feed (e.g. gastrostomy and jejunostomy) or to flush the intestines.
Colostomy or ileostomy can bypass affected parts if they are distal to (come after) the stoma. For instance, if only the colon is affected, an ileostomy may be helpful. Either of these ostomies are typically placed at or a few centimeters below the patient's navel per doctor recommendation based on the affected area of the intestines as well as concerns for patient comfort and future physical growth for children. [29]
The total removal of the colon, called a colectomy or resection of affected parts of the colon may be needed if part of the gut dies (for instance toxic megacolon), or if there is a localized area of dysmotility.
Gastric and colonic pacemakers have been tried. These are strips placed along the colon or stomach which create an electric discharge intended to cause the muscle to contract in a controlled manner.
A potential solution, albeit radical, is intestinal transplantation. This is only appropriate in the case of intestinal failure. These procedures are most frequently described in pediatric cases of CIPO. [30] [31] One operation involving multi-organ transplant of the pancreas, stomach, duodenum, small intestine, and liver, and was performed by Doctor Kareem Abu-Elmagd on Gretchen Miller. [32]
Further research is necessary into other treatments which may alleviate symptoms. These include stem-cell transplantation [9] [33] [34] and fecal microbiota transplantation. [9] Cannabis [35] has not been studied with regards to CIPO. Any claims to its efficacy for use in CIPO are speculative.
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.
Enteritis is inflammation of the small intestine. It is most commonly caused by food or drink contaminated with pathogenic microbes, such as Serratia, but may have other causes such as NSAIDs, radiation therapy as well as autoimmune conditions like coeliac disease. Symptoms include abdominal pain, cramping, diarrhoea, dehydration, and fever. Related diseases of the gastrointestinal system involve inflammation of the stomach and large intestine.
Inflammatory bowel disease (IBD) is a group of inflammatory conditions of the colon and small intestine, with Crohn's disease and ulcerative colitis (UC) being the principal types. Crohn's disease affects the small intestine and large intestine, as well as the mouth, esophagus, stomach and the anus, whereas UC primarily affects the colon and the rectum.
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.
Malabsorption is a state arising from abnormality in absorption of food nutrients across the gastrointestinal (GI) tract. Impairment can be of single or multiple nutrients depending on the abnormality. This may lead to malnutrition and a variety of anaemias.
Functional gastrointestinal disorders (FGID), also known as disorders of gut–brain interaction, include a number of separate idiopathic disorders which affect different parts of the gastrointestinal tract and involve visceral hypersensitivity and motility disturbances.
Gastrointestinal diseases refer to diseases involving the gastrointestinal tract, namely the esophagus, stomach, small intestine, large intestine and rectum; and the accessory organs of digestion, the liver, gallbladder, and pancreas.
Small intestinal bacterial overgrowth (SIBO), also termed bacterial overgrowth, or small bowel bacterial overgrowth syndrome (SBBOS), is a disorder of excessive bacterial growth in the small intestine. Unlike the colon, which is rich with bacteria, the small bowel usually has fewer than 100,000 organisms per millilitre. Patients with bacterial overgrowth typically develop symptoms which may include nausea, bloating, vomiting, diarrhea, malnutrition, weight loss, and malabsorption by various mechanisms.
Short bowel syndrome is a rare malabsorption disorder caused by a lack of functional small intestine. The primary symptom is diarrhea, which can result in dehydration, malnutrition, and weight loss. Other symptoms may include bloating, heartburn, feeling tired, lactose intolerance, and foul-smelling stool. Complications can include anemia and kidney stones.
Intestinal malrotation is a congenital anomaly of rotation of the midgut. It occurs during the first trimester as the fetal gut undergoes a complex series of growth and development. Malrotation can lead to a dangerous complication called volvulus, in which cases emergency surgery is indicated. Malrotation can refer to a spectrum of abnormal intestinal positioning, often including:
Lymphangiectasia, also known as "lymphangiectasis", is a pathologic dilation of lymph vessels. When it occurs in the intestines it is known as intestinal lymphangiectasia, colloquially recognized as Waldmann's disease in cases where there is no secondary cause. The primary defect lies in the inability of the lymphatic system to adequately drain lymph, resulting in its subsequent accumulation and leakage into the intestinal lumen. This condition, first described by Waldmann in 1961, is typically diagnosed in infancy or early childhood. However, it can also manifest in adults, exhibiting a broad spectrum of clinical symptoms.
Ogilvie syndrome, or acute colonic pseudo-obstruction is the acute dilatation of the colon in the absence of any mechanical obstruction in severely ill patients.
Chronic intestinal pseudo-obstruction (CIPO) is an uncommon syndrome with chronic and recurrent symptoms that suggest intestinal obstruction in the absence of any mechanical blockage of the lumen. The most common symptoms of CIPO include abdominal pain, constipation, nausea, vomiting, dysphagia, and abdominal distention. CIPO can lead to malnutrition.
Mitochondrial neurogastrointestinal encephalopathy syndrome (MNGIE) is a rare autosomal recessive mitochondrial disease. It has been previously referred to as polyneuropathy, ophthalmoplegia, leukoencephalopathy, and intestinal pseudoobstruction. The disease presents in childhood, but often goes unnoticed for decades. Unlike typical mitochondrial diseases caused by mitochondrial DNA (mtDNA) mutations, MNGIE is caused by mutations in the TYMP gene, which encodes the enzyme thymidine phosphorylase. Mutations in this gene result in impaired mitochondrial function, leading to intestinal symptoms as well as neuro-ophthalmologic abnormalities. A secondary form of MNGIE, called MNGIE without leukoencephalopathy, can be caused by mutations in the POLG gene.
Gastroparesis, also called delayed gastric emptying, is a medical disorder consisting of weak muscular contractions (peristalsis) of the stomach, resulting in food and liquid remaining in the stomach for a prolonged period of time. Stomach contents thus exit more slowly into the duodenum of the digestive tract. This can result in irregular absorption of nutrients, inadequate nutrition, and poor glycemic control. The opposite of this, where stomach contents exit quickly into the duodenum, is called dumping syndrome.
Superior mesenteric artery (SMA) syndrome is a gastro-vascular disorder in which the third and final portion of the duodenum is compressed between the abdominal aorta (AA) and the overlying superior mesenteric artery. This rare, potentially life-threatening syndrome is typically caused by an angle of 6–25° between the AA and the SMA, in comparison to the normal range of 38–56°, due to a lack of retroperitoneal and visceral fat. In addition, the aortomesenteric distance is 2–8 millimeters, as opposed to the typical 10–20. However, a narrow SMA angle alone is not enough to make a diagnosis, because patients with a low BMI, most notably children, have been known to have a narrow SMA angle with no symptoms of SMA syndrome.
Waldmann disease, also known as Primary Intestinal Lymphangiectasia (PIL), is a rare disease characterized by enlargement of the lymph vessels supplying the lamina propria of the small intestine. Although its prevalence is unknown, it being classified as a "rare disease" means that less than 200,000 of the population of the United States are affected by this condition and its subtypes and there have been approximately 50 reported cases of adult-onset PIL since 1961.
Chronic diarrheaof infancy, also called toddler's diarrhea, is a common condition typically affecting up to 1.7 billion children between ages 6–30 months worldwide every year, usually resolving by age 4. According to the World Health Organization (WHO), diarrheal disease is the second greatest cause of death in children 5 years and younger. Diarrheal disease takes the lives of 525,000 or more children per year. Diarrhea is characterized as the condition of passing of three or more loose or watery bowel movements within a day sometimes with undigested food visible. Diarrhea is separated into three clinical categories; acute diarrhea may last multiple hours or days, acute bloody diarrhea, also known as dysentery, and finally, chronic or persistent diarrhea which lasts 2–4 weeks or more. There is normal growth with no evidence of malnutrition in the child experiencing persistent diarrhea. In chronic diarrhea there is no evidence of blood in the stool and there is no sign of infection. The condition may be related to irritable bowel syndrome. There are various tests that can be performed to rule out other causes of diarrhea that don't fall under the chronic criteria, including blood test, colonoscopy, and even genetic testing. Most acute or severe cases of diarrhea have treatment guidelines revolving around prescription or non prescription medications based on the cause, but the treatment protocols for chronic diarrhea focus on replenishing the body with lost fluids and electrolytes, because there typically isn't a treatable cause.
Bile acid malabsorption (BAM), known also as bile acid diarrhea, is a cause of several gut-related problems, the main one being chronic diarrhea. It has also been called bile acid-induced diarrhea, cholerheic or choleretic enteropathy, bile salt diarrhea or bile salt malabsorption. It can result from malabsorption secondary to gastrointestinal disease, or be a primary disorder, associated with excessive bile acid production. Treatment with bile acid sequestrants is often effective. It is recognised as a disability in the United Kingdom under the Equality Act 2010
Intestine transplantation is the surgical replacement of the small intestine for chronic and acute cases of intestinal failure. While intestinal failure can oftentimes be treated with alternative therapies such as parenteral nutrition (PN), complications such as PN-associated liver disease and short bowel syndrome may make transplantation the only viable option. One of the rarest type of organ transplantation performed, intestine transplantation is becoming increasingly prevalent as a therapeutic option due to improvements in immunosuppressive regimens, surgical technique, PN, and the clinical management of pre and post-transplant patients.
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