Strictures in Crohn's Disease

CD is characterized by inflammation that tends to involve the deeper layers of the intestines. Strictures, therefore, are more commonly found in CD than in UC. What is more, strictures in CD may be found anywhere in the gut. Remember that the intestinal inflammation in UC is confined to the inner lining (mucosa) of the colon. Accordingly, in chronic UC, benign (meaning not malignant) strictures of the colon occur only rarely. In fact, a narrowed segment of the colon in UC may well be caused by a colon cancer rather than by a benign (non-cancerous), chronic inflammatory stricture.

What symptoms do intestinal strictures cause and how are they diagnosed?

Patients may not know that they have an intestinal stricture. The stricture may not cause symptoms if it is not causing significant blockage (obstruction) of the bowel. If a stricture is narrow enough to hinder the smooth passage of the bowel contents, however, it may cause abdominal pain, cramps, and bloating (distention). If the stricture causes an even more complete obstruction of the bowel, patients may experience more severe pain, nausea, vomiting, and an inability to pass stools.

An intestinal obstruction that is caused by a stricture can also lead to perforation of the bowel. The bowel must increase the strength of its contractions to push the intestinal contents through a narrowing in the bowel. The contracting segment of the intestine above the stricture, therefore, may experience an increased pressure. This pressure sometimes weakens the bowel wall in that area, thereby causing the intestines to become abnormally wide (dilated). If the pressure becomes too high, the bowel wall may then rupture (perforate). This perforation can result in a severe infection of the abdominal cavity (peritonitis), abscesses (collections of infection and pus), and fistulas (tubular passageways originating from the bowel wall and connecting to other organs or the skin). Strictures of the small bowel also can lead to bacterial overgrowth, which is yet another intestinal complication of IBD.

Intestinal strictures of the small intestine may be diagnosed with a small bowel follow-through (SBFT) x-ray. For this study, the patient swallows barium, which outlines the inner lining of the small intestine. Thus, the x-ray can show the width of the passageway, or lumen, of the intestine. Upper GI endoscopy (EGD) and enteroscopy are also used for locating strictures in the small intestine. For suspected strictures in the colon, barium can be inserted into the colon (barium enema), followed by an x-ray to locate the strictures. Colonoscopy is another diagnostic option.

How are intestinal strictures in IBD treated?

Intestinal strictures may be composed of a combination of scar tissue (fibrosis) and tissue that is inflamed and, therefore, swollen. A logical and sometimes effective treatment for these strictures, therefore, is medication to decrease the inflammation. Some medications for IBD, such as infliximab, however, may make some strictures worse. The reason is that these medications may actually promote the formation of scar tissue during the healing process. If the stricture is predominantly scar tissue and is only causing a mild narrowing, symptoms may be controlled simply by changes in the diet. For example, the patient should avoid high fibre foods, such as raw carrots, celery, beans, seeds, nuts, fiber, bran, and dried fruit.

If the stricture is more severe and can be reached and examined with an endoscope, it may be treated by stretching (dilation) during the endoscopy. In this procedure, special instruments are used through the endoscope to stretch open the stricture. Typically, however, this procedure does not produce long lasting results.

Surgery sometimes is needed to treat intestinal strictures. The operation may involve cutting out (resecting) the entire narrowed segment of bowel, especially if it is a long stricture. More recently, a more limited operation, called stricturoplasty, has been done. In this procedure, the surgeon simply cuts open the strictured segment lengthwise and then sews the tissue closed crosswise so as to enlarge the width of the bowel's passageway (lumen). After surgery in CD patients, medication still should be taken to prevent inflammation from recurring, especially at the site of the stricture. The reason for this recommendation is that after abdominal operations, recurrent intestinal inflammation is a common problem in CD. Furthermore, the risk of post-operative intestinal fistulas and abscesses is increased in CD patients. Therefore, only abdominal surgery that is absolutely necessary should be done in patients with CD.

Updated July 2003