The average age of onset for collagenous colitis is in the 50s. This condition tends to affect more women than men. The average age of onset for lymphocytic colitis is in the 60s, and women seem to be affected slightly more often than men. There has not been a lot of research on MC, so it's not known how common it is.
Causes
The cause of MC is currently unknown. One theory is that the use of non-steroidal-anti-inflammatory drugs (such as ibuprofen) may contribute to the development of MC. Another theory is that MC is caused by an autoimmune response, where the body’s immune system attacks other tissues in the body.It is also thought that bacteria or viruses may play a role in the development of MC, but the exact relationship is unknown.
Signs and Symptoms
The symptoms of MC are chronic, watery diarrhea, sometimes accompanied by cramps and abdominal pain. The diarrhea could range from being continuous and severe to intermittent. Blood in the stool is not a symptom of MC.Other symptoms could include fever, joint pain, and fatigue. These symptoms may be a result of the inflammatory process that is part of an autoimmune disease.
Diagnosis
In MC, the colon generally appears normal on sight. Therefore, a colonoscopy or sigmoidoscopy might not show any evidence of disease. In some patients there may be areas of swelling or redness in the colon, but these may be difficult to see.In order to make a diagnosis, several biopsies must be taken from the colon. These biopsies will preferably come from several different areas in the colon. The hallmark signs of the disease can then be seen microscopically, hence the name of “microscopic” colitis.
Collagen is a substance that is normally present under the lining of the colon. In collagenous colitis, biopsies will show larger than normal amounts of collagen beneath the lining of the colon. A biopsy may also show an increased number of lymphocytes, a type of white blood cell.
In lymphocytic colitis, a biopsy will show increased lymphocytes. The absence of collagen in a biopsy is also an indication that the diagnosis is lymphocytic colitis and not collagenous colitis.
Treatment
Some cases of MC may resolve on their own. For those cases that require intervention, treatment may be initially started with the addition of fiber supplements to the diet. Fiber supplements include psyllium, methylcellulose, or polycarbophil. Because the main symptom of MC is chronic diarrhea, treatment may also include an anti-diarrheal medication such as loperamide or diphenoxylate.For more severe cases of MC, antibiotics or anti-inflammatory drugs may also be prescribed. Many of the anti-inflammatories used for MC are the same as those used to treat inflammatory bowel disease: mesalamine, sulfasalazine, and budesonide. Corticosteroids may also be used, with the goal of discontinuing their use as soon as symptoms are under control.
Sources:
Crohn’s and Colitis Foundation of America. "Microscopic and ischemic colitis." Crohn’s and Colitis Foundation of America. 22 September 2005. 26 Nov 2006.
Yao, Patrick, MD. "Microscopic Colitis." UCLA Department of Medicine 23 September 2005. UCLA Department of Medicine. 26 Nov 2006.
The National Digestive Diseases Information Clearinghouse. "Collagenous Colitis and Lymphocytic Colitis." The National Digestive Diseases Information Clearinghouse. January 2006. 26 Nov 2006.
