Collagenous colitis is a specific type of inflammatory bowel disease affecting the colon. It is characterized by chronic diarrhea that typically does not contain blood. Collagenous colitis is one of two forms of microscopic colitis, so named because these diseases cannot usually be diagnosed by viewing the colon by means of a colonoscopy. In order to definitively diagnose one of the microscopic colitis diseases, it is normally necessary for a doctor to take a biopsy of the colon tissue and examine it under a microscope. The two types of microscopic colitis are collagenous and lymphocytic colitis.
Adults aged over 40 years old are typically the susceptible age group in which Collagenous colitis most often occurs. The exact cause of the disease is not known. The inflammation in the colon may be due to a bacterial or viral agent, or may possibly indirectly be caused by toxic substances produced by such pathogens. Some doctors believe that the disease may be related to an autoimmune reaction, where the patient’s immune system attacks healthy cells.
Collagenous colitis symptoms include cramping or pain in the abdomen. The most important symptom, however, is the chronic discharge of a watery, non-bloody diarrhea. This may be quite constant, or may stop and start.
Collagenous colitis treatment includes a variety of different medications. Anti-inflammatory drugs are often prescribed in the first instance. Subsequent treatment may include steroids, but long-term use of these is not recommended as it may lead to serious side effects including loss of bone density, and an increase in blood pressure. Other drugs that may be used as a treatment for collagenous colitis include various substances that suppress the immune system, and thus may reduce inflammation, but these are not usually prescribed unless the condition does not respond to other treatment options.
In some cases, no drug treatment is necessary, and having the patient follow a diet for collagenous colitis may be sufficient to cure the disease. Doctors will often recommend a reduction of dietary fat along with the removal of dairy products, caffeine, and aspirin and other pain relief medication. If the disease does not respond to either medication or a change in diet, then in extreme cases a full or partial colectomy is necessary. In this treatment, all or part of the colon is surgically removed. Such extreme treatment for collagenous colitis is rarely needed, however.