Rectal stricture

Last updated
Rectal stricture
Other namesRectal stenosis
Specialty Colorectal surgery

A rectal stricture (rectal stenosis) [1] is a chronic and abnormal narrowing or constriction of the lumen of the rectum which presents a partial or complete obstruction to the movement of bowel contents. A rectal stricture is located deeper inside the body compared to an anal stricture. Sometimes other terms with wider meaning are used, such as anorectal stricture, colorectal stricture or rectosigmoid stricture.

Contents

Definition

Rectal stricture has been defined as the inability to pass a rigid proctoscope (12 mm diameter) or a rigid sigmoidoscope (19 mm diameter) through the affected cross-section of rectum. [1] If the rectal stricture is accessible during digital rectal examination, a rectal stricture may be defined as narrowing to less than one-finger breadth. [2]

Anal stricture versus rectal stricture

Anal strictures are usually located at the anal verge in a narrow band, but sometimes they involve the entire length of the anal canal. [1] Surgeons and anatomists have different definitions of the anal canal. [3] Surgically and clinically, the anal canal is usually defined as the zone from the anal verge to the anorectal ring (at the level of the external anal sphincter and the puborectalis muscle). The anorectal ring is easy to identify when patients are asked to squeeze during digital rectal examination. [3] Anatomically, the anal canal is defined as the zone from the anal verge to the dentate line (pectinate line). [3] This is a line formed by the lower ends of the anal columns and represents the embryological junction between the hindgut and the proctodeum. [3]

Both rectal stricture and anal stricture (anal stenosis) are types of colonic stricture. They both can also be more widely categorized as gastrointestinal strictures. However, rectal strictures behave differently to colonic strictures because of the proximity of the rectum to the anal canal and pelvic organs, and because of different blood supply. [2]

Signs and symptoms

There may be no symptoms (clinically silent stricture), [4] or only minor symptoms, but may get worse over time. [2] On the other hand, acute bowel obstruction may develop as the first major sign of a stricture. This may be the case with malignant strictures, and the condition may be a medical emergency which requires urgent treatment in order to avoid serious complications such as bowel perforation. [5] When symptoms are caused, the term "clinically relevant rectal stricture" is used. [1] Possible symptoms include:

Diagnosis

The first step is exclusion of malignant causes. This may involve tissue biopsy, endorectal ultrasound, computed tomography, and magnetic resonance imaging. [1] The next step is assessment of the stricture. The distance from the anal verge, the diameter of the narrowest point of the stricture, and the longitudinal length are ascertained. The degree of narrowing can be assessed with a water-soluble contrast enema. [1]

Classification

Rectal strictures are usually classified as benign or malignant (associated with cancer).

Benign

Benign rectal strictures can be further subcategorized as primary (caused by diseases) and secondary (caused by complication of surgery). Secondary strictures very often occur at the site of a previous surgical anastomosis. Primary strictures have various causes, including different inflammatory disease processes. Causes of benign strictures include:

Malignant

Acute bowel obstruction is a common presenting manifestation of colorectal cancer which is locally advanced. [5] Malignant strictures may also develop in the context of inflammatory bowel disease. Treatment for malignant strictures is ideally resection (surgical removal) with or without radiotherapy. If resection is not possible or not sensible, symptoms of the stricture may be palliated with radiotherapy, stents, or debulking. [1] Possible malignant processes which may cause rectal stricture include:

Causes

The narrowing may be because of an intrinsic process occurring within the lumen of the rectum (luminal), within the wall of the rectum (mural), or it can be due to an extrinsic process that is compressing the rectum from the outside (extramural). [1] [8] In the case of external compression of the bowel, the term pseudostricture may be used. [9]

According to one review of a total of 730 cases, those which formed after anastomosis represented 74% of all reported benign rectal strictures. [2] The next most common cause of benign rectal stricture was inflammatory bowel disease, accounting for 20% of all cases. [2] This means all other causes of rectal stricture are, by comparison, rare.

Anastomosis

Rectal stricture is reported to develop after colorectal resection at a rate of 3-30%. Such strictures mostly form after resection due to rectal cancer with colorectal or coloanal anastomosis. Stricture is also possible as a complication following resection because of diverticular disease. According to some reports, rectal strictures are more likely following stapled anastomosis compared to hand sutured anastomosis. [2] However, a Cochrane review found no significant difference in the rate of rectal stricture between hand sewn and stapled ileocolic anastomosis (usually performed after right‐sided colon cancer and Crohn's disease). [10]

Inflammatory bowel disease

Inflammatory bowel diseases (IBD) include Crohn’s disease, which affects only the colon, and ulcerative colitis, which may affect any section of the gastrointestinal tract. The relapsing-remitting, chronic inflammation in the bowel wall non uncommonly leads to the development of colonic strictures, including rectal strictures. [6] Rectal strictures are more common in Crohn's disease than in ulcerative colitis. [2] There is a risk of malignancy developing at the site of stricture. Therefore, tissue biopsy of strictures is carried out in order to check for dysplasia or malignancy.

Trauma

Stricture may occur following trauma such as caustic burns caused by chemical agents. [11] [12] If they cause inflammation, chronic use of suppositories may cause rectal stricture, [2] but overall this is a safe method of drug delivery. [13]

Thermal burns are possible if hot water enemas are attempted by patients or practitioners of alternative medicine in the belief that they will provide a stronger stimulus for evacuation of stool. [11] The rectal mucosa is vulnerable to thermal burns in such cases because it is sensitive only to distension (stretching) and not to thermal stimuli. [11] Usually a burn of the rectal wall heals after 2–3 weeks without permanent stricture. Such burns may be treated with bowel resting, antibiotics, stool softeners, liquid diet and steroid suppository to reduce inflammation. [11] Sometimes thermal burns progress to chronic stricture. [11]

Radiation

The rectum is very close to the prostate in males and the uterus and cervix in females, and therefore it frequently receives radiation during radiotherapy for cancers in the pelvic region. Radiation proctitis (chronic radiation enterocolitis) usually appears after several months of treatment, and is characterized by rectal bleeding or obstructed defecation secondary to the formation of strictures. [7] Such rectal strictures are usually located in the proximal rectum, and are one of the most common features of late radiation damage. [14] The mechanism of stricture formation is obliterative endarteritis, lymphatic dilation, and tissue ischemia and necrosis. [7] Then there is collagen deposition and fibrosis in the submucosal layer. [7] They are often associated with a fistula. [14] Post-irradiation strictures may cause symptoms such as diarrhea, tenesmus, narrow feces, abdominal pain, and vomiting. [7] The risk of intestinal obstruction due to strictures in patients receiving radiotherapy in the pelvis is reported as 1–15%. [7]

Infection

Sexually transmitted infections may sometimes cause rectal strictures in persons who engage in anoreceptive sex. [2] Lymphogranuloma venereum usually affects the genital mucosa. However, it may rarely present as the anorectal variant, termed "lymphogranuloma venereum proctitis". Lymph nodes are enlarged and suppurative (produce pus). The condition is similar to Crohn's disease with rectal stricture formation (eventually), bowel perforation and fistulae. [15] In one report, herpes simplex virus 2 was implicated as the cause of a rectal stricture. [2] Rarely, rectal stricture may develop in actinomycosis infection. [2]

Other

If a foreign body becomes stuck there is reactive inflammation and fibrosis, which eventually may lead to the formation of a stricture. [2] In endometriosis, if ectopic endometrial tissue is present in the rectal wall it may cause rectal stricture. [2] Solitary rectal ulcer syndrome may also sometimes be associated with rectal stricture. [2]

Rectal stricture may sometimes be a complication of surgical procedures other than anastomosis. For example, endoscopic submucosal dissection, which is a minimally invasive treatment for colorectal cancer, may rarely cause development of a rectal stricture. [2] Other surgical procedures which may cause the development of a stricture include ventral rectopexy, [8] Delorme’s procedure, [16] and hemorrhoidectomy.

Treatment

How a rectal stricture is treated depends on the exact cause, the distance from the anal verge, the degree of narrowing, the severity of symptoms, and the health of the patient. [1] Short strictures are more responsive to dilation. Longer strictures may require more significant surgical procedures. [1] Generally, benign rectal strictures may not require treatment if they do not cause symptoms. [1] For example, a non symptomatic stricture may be detected as an incidental finding during colonoscopy for an unrelated reason. [1] Treatment options fall into 3 main categories: dilatation, stenting, or surgery. [11]

Non surgical treatment

The treatment depends on the cause. For example, strictures caused by infections may respond well to antibiotics. [2] Use of stool softeners, laxatives and high fiber diet is a general measure for most strictures, and is also sometimes advised for prevention of recurrence of stricture even after treatment. [2] Non surgical treatment may be combined with other procedures such as dilation. Steroids may be injected into the stricture. It is unknown exactly how the steroid helps to prevent recurrence of the stricture, but it may involve inhibition of collagen formation and cross-linking, and increase of collagen breakdown. In combination, this reduces contraction of scar tissue. [7] TNF inhibitors such as infliximab have also been injected into strictures endoscopically. However, this is not a common treatment. [6] Healing of rectal strictures in inflammatory bowel disease with TNF inhibitor occurs in 59% of cases. [2] Mitomycin C has been used as a topical application, in combination with manual dilation. [17]

Dilation

For rectal strictures which are mild and close to the anal verge (<6 cm), digital dilation (with fingers) or dilation with instruments is possible. [1] Such instruments include Hagar's dilators, esophageal dilators, St Marks anal dilators, and bougie dilators. [16] [1] [2] Sometimes the patient can be shown how to perform this dilation at home, but this is may be difficult for them, and rarely gives good long term results. [16] Dilation with instruments by the surgeon may be performed under sedation or under general aesthesia for moderate strictures. [16] This treatment is often the first to be attempted, and is successful about 50% of the time. [2] Hegar dilators come in multiple sizes with different diameters. This enables progressive dilation over time which reduces the risk of bowel perforation. [1]

Balloon dilation is the most common method of mechanical dilation, [11] and is also often considered the first line treatment. [2] This treatment is simple, but repeat procedures may be needed. [11] Balloon dilation may be combined with intralesional steroid injection. [7] Injection of steroid seems to increase the effectiveness of balloon dilation, and increases the length of time before relapse. [7] The success rate of balloon dilation for benign rectal strictures overall is about 78%. [2] In rectal strictures in the context of Crohn's disease, the long-term success rate of balloon dilation is about 80%. However, it may be ineffective for very tight, fibrotic strictures. [17] Fluoroscopic guidance can be used during the procedure to improve visualization. [2] The risk of bowel perforation is about 1%. [2]

Surgery

Surgical procedures are indicated if multiple other treatments have failed, or if the stricture involves a long section of bowel. [11] Surgical procedures may be carried out by the transanal approach or via the transabdominal approach. [11] Debulking of malignant strictures may be carried out with laser ablation or with argon beam plasma coagulation. [1] Various procedures and methods have been used to surgically treat strictures, including:

Stents

Self-expandable metallic stents (SEMS) are sometimes used, but they are usually considered not suitable for very low rectal strictures. [14] However, this view is now challenged. [18] Stents may be used as the definitive treatment of a stricture, or as a temporary measure to stabilize a patient with acute obstruction before another procedure is carried out. [11] Stents are not commonly used for benign rectal strictures. [11] Sometimes they are used when strictures are associated with malignancy. In such cases, use of a stent may avoid or delay the need for colostomy. [19]

Related Research Articles

<span class="mw-page-title-main">Gastroenterology</span> Branch of medicine focused on the digestive system and its disorders

Gastroenterology is the branch of medicine focused on the digestive system and its disorders. The digestive system consists of the gastrointestinal tract, sometimes referred to as the GI tract, which includes the esophagus, stomach, small intestine and large intestine as well as the accessory organs of digestion which include the pancreas, gallbladder, and liver.

<span class="mw-page-title-main">Defecation</span> Expulsion of feces from the digestive tract

Defecation follows digestion, and is a necessary process by which organisms eliminate a solid, semisolid, or liquid waste material known as feces from the digestive tract via the anus or cloaca. The act has a variety of names ranging from the common, like pooping or crapping, to the technical, e.g. bowel movement, to the obscene (shitting), to the euphemistic, to the juvenile. The topic, usually avoided in polite company, can become the basis for some potty humor.

<span class="mw-page-title-main">Constipation</span> Infrequent or difficult bowel movements

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">Fecal incontinence</span> Inability to refrain from defecation

Fecal incontinence (FI), or in some forms, encopresis, is a lack of control over defecation, leading to involuntary loss of bowel contents — including flatus (gas), liquid stool elements and mucus, or solid feces. FI is a sign or a symptom, not a diagnosis. Incontinence can result from different causes and might occur with either constipation or diarrhea. Continence is maintained by several interrelated factors, including the anal sampling mechanism, and incontinence usually results from a deficiency of multiple mechanisms. The most common causes are thought to be immediate or delayed damage from childbirth, complications from prior anorectal surgery, altered bowel habits. An estimated 2.2% of community-dwelling adults are affected. However, reported prevalence figures vary. A prevalence of 8.39% among non-institutionalized U.S adults between 2005 and 2010 has been reported, and among institutionalized elders figures come close to 50%.

<span class="mw-page-title-main">Bowel obstruction</span> Mechanical or functional obstruction of the intestines

Bowel obstruction, also known as intestinal obstruction, is a mechanical or functional obstruction of the intestines which prevents the normal movement of the products of digestion. Either the small bowel or large bowel may be affected. Signs and symptoms include abdominal pain, vomiting, bloating and not passing gas. Mechanical obstruction is the cause of about 5 to 15% of cases of severe abdominal pain of sudden onset requiring admission to hospital.

<span class="mw-page-title-main">Rectal prolapse</span> Protrusion of the walls of the rectum outside the body

A rectal prolapse occurs when walls of the rectum have prolapsed to such a degree that they protrude out of the anus and are visible outside the body. However, most researchers agree that there are 3 to 5 different types of rectal prolapse, depending on whether the prolapsed section is visible externally, and whether the full or only partial thickness of the rectal wall is involved.

<span class="mw-page-title-main">Colorectal surgery</span> Field in medicine for disabilities in the rectum

Colorectal surgery is a field in medicine dealing with disorders of the rectum, anus, and colon. The field is also known as proctology, but this term is now used infrequently within medicine and is most often employed to identify practices relating to the anus and rectum in particular. The word proctology is derived from the Greek words πρωκτός proktos, meaning "anus" or "hindparts", and -λογία -logia, meaning "science" or "study".

<span class="mw-page-title-main">Ileostomy</span> Surgical procedure

Ileostomy is a stoma constructed by bringing the end or loop of small intestine out onto the surface of the skin, or the surgical procedure which creates this opening. Intestinal waste passes out of the ileostomy and is collected in an external ostomy system which is placed next to the opening. Ileostomies are usually sited above the groin on the right hand side of the abdomen.

In medicine, the ileal pouch–anal anastomosis (IPAA), also known as restorative proctocolectomy (RPC), ileal-anal reservoir (IAR), an ileo-anal pouch, ileal-anal pullthrough, or sometimes referred to as a J-pouch, S-pouch, W-pouch, or a pelvic pouch, is an anastomosis of a reservoir pouch made from ileum to the anus, bypassing the former site of the colon in cases where the colon and rectum have been removed. The pouch retains and restores functionality of the anus, with stools passed under voluntary control of the person, preventing fecal incontinence and serving as an alternative to a total proctocolectomy with ileostomy.

Proctitis or anusitis is an inflammation of the anus and the lining of the rectum, affecting only the last 6 inches of the rectum.

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

Blood in stool 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.

Pouchitis is an umbrella term for inflammation of the ileal pouch, an artificial rectum surgically created out of ileum in patients who have undergone a proctocolectomy or total colectomy. The ileal pouch-anal anastomosis is created in the management of patients with ulcerative colitis, indeterminate colitis, familial adenomatous polyposis, cancer, or rarely, other colitides.

Rectal bleeding refers to bleeding in the rectum, thus a form of lower gastrointestinal bleeding. 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">Bowel resection</span> Surgical procedure in which a part of an intestine is removed

A bowel resection or enterectomy is a surgical procedure in which a part of an intestine (bowel) is removed, from either the small intestine or large intestine. Often the word enterectomy is reserved for the sense of small bowel resection, in distinction from colectomy, which covers the sense of large bowel resection. Bowel resection may be performed to treat gastrointestinal cancer, bowel ischemia, necrosis, or obstruction due to scar tissue, volvulus, and hernias. Some patients require ileostomy or colostomy after this procedure as alternative means of excretion. Complications of the procedure may include anastomotic leak or dehiscence, hernias, or adhesions causing partial or complete bowel obstruction. Depending on which part and how much of the intestines are removed, there may be digestive and metabolic challenges afterward, such as short bowel syndrome.

<span class="mw-page-title-main">Self-expandable metallic stent</span>

A self-expandable metallic stent is a metallic tube, or stent that holds open a structure in the gastrointestinal tract to allow the passage of food, chyme, stool, or other secretions related to digestion. Surgeons insert SEMS by endoscopy, inserting a fibre optic camera—either through the mouth or colon—to reach an area of narrowing. As such, it is termed an endoprosthesis. SEMS can also be inserted using fluoroscopy where the surgeon uses an X-ray image to guide insertion, or as an adjunct to endoscopy.

<span class="mw-page-title-main">Colorectal polyp</span> Growth found in bowel wall

A colorectal polyp is a polyp occurring on the lining of the colon or rectum. Untreated colorectal polyps can develop into colorectal cancer.

Rectal discharge is intermittent or continuous expression of liquid from the anus. Normal rectal mucus is needed for proper excretion of waste. Otherwise, this is closely related to types of fecal incontinence but the term rectal discharge does not necessarily imply degrees of incontinence. Types of fecal incontinence that produce a liquid leakage could be thought of as a type of rectal discharge.

Solitary rectal ulcer syndrome or SRUS is a chronic disorder of the rectal mucosa. It commonly occurs with varying degrees of rectal prolapse. The condition is thought to be caused by different factors, such as long term constipation, straining during defecation, and dyssynergic defecation. Treatment is by normalization of bowel habits, biofeedback, and other conservative measures. In more severe cases various surgical procedures may be indicated. The condition is relatively rare, affecting approximately 1 in 100,000 people per year. It affects mainly adults aged 30–50. Females are affected slightly more often than males. The disorder can be confused clinically with rectal cancer or other conditions such as inflammatory bowel disease, even when a biopsy is done.

<span class="mw-page-title-main">Anismus</span> Failure to relax the pelvic floor muscles during defecation

Anismus or dyssynergic defecation is the failure of normal relaxation of pelvic floor muscles during attempted defecation. It can occur in both children and adults, and in both men and women. It can be caused by physical defects or it can occur for other reasons or unknown reasons. Anismus that has a behavioral cause could be viewed as having similarities with parcopresis, or psychogenic fecal retention.

Obstructed defecation syndrome is a major cause of functional constipation, of which it is considered a subtype. It is characterized by difficult and/or incomplete emptying of the rectum with or without an actual reduction in the number of bowel movements per week. Normal definitions of functional constipation include infrequent bowel movements and hard stools. In contrast, ODS may occur with frequent bowel movements and even with soft stools, and the colonic transit time may be normal, but delayed in the rectum and sigmoid colon.

References

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  10. ↑ Choy, PY; Bissett, IP; Docherty, JG; Parry, BR; Merrie, A; Fitzgerald, A (7 September 2011). "Stapled versus handsewn methods for ileocolic anastomoses". The Cochrane Database of Systematic Reviews (9): CD004320. doi:10.1002/14651858.CD004320.pub3. PMID   21901690.
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