What Is Collagenous Colitis?
Inflammatory bowel disease (IBD) is a general name for diseases that cause inflammation in the intestines. Collagenous colitis is a type of bowel inflammation that affects the
colon (large intestine). Collagenous colitis is not related to
Crohn's disease or
ulcerative colitis, which are more severe forms of inflammatory bowel disease. Also, collagenous colitis does not increase the risk of
colon cancer.
Collagenous colitis and another type of colitis, called
lymphocytic colitis, are referred to as
microscopic colitis because
colonoscopy usually shows no signs of inflammation on the surface of the colon. Instead, tissue samples from the colon must be examined under a microscope to make the diagnosis.
No precise cause of this disorder has been found. Possible causes of damage to colon's lining include:
- Bacteria and their toxins
- Viruses
- Nonsteroidal anti-inflammatory drugs (NSAIDs).
Some researchers have suggested that collagenous colitis results from an autoimmune response, meaning that the body's immune system is destroying cells for no apparent reason.
Symptoms of Collagenous Colitis
Collagenous colitis symptoms can include:
- Chronic watery diarrhea that isn't bloody -- the diarrhea may be continuous or come in episodes
- Abdominal pain or cramps may also be present.
A collagenous colitis diagnosis is made after tissue samples taken during
colonoscopy (or flexible
sigmoidoscopy) are examined under a microscope. Collagenous colitis is characterized by a larger-than-normal band of protein called collagen inside the lining of the
colon. The thickness of the band varies, so multiple tissue samples from different areas of the colon may need to be examined.
People with collagenous colitis are most often diagnosed in their 50s, although some cases have been reported in adults younger than 45 years and in children between the ages of 5 and 12. It is diagnosed more frequently in women than in men.
Treatment for Collagenous Colitis
Collagenous colitis treatment varies depending on the symptoms and severity of the disease. It has been known to go away on its own, but most people with this condition have recurrent symptoms.
Lifestyle changes aimed at improving
diarrhea are usually tried first. Recommended changes include:
- Reducing the amount of fat in the diet
- Eliminating foods that contain caffeine or lactose
- Not using NSAIDs.
If lifestyle changes alone are not enough, medications are often used to control the symptoms of collagenous colitis.
Antidiarrheal medications (such as bismuth subsalicylate) and bulking agents (such as fiber supplements) can help reduce diarrhea. Anti-inflammatory medications, such as
mesalamine,
sulfasalazine, and steroids (including
budesonide), reduce inflammation. Immunosuppressive agents, which reduce the autoimmune response, are rarely needed.
For very extreme cases of collagenous colitis, bypass of the colon or surgery to remove all or part of the colon have been done on occasion. However, these surgeries are rarely recommended.
