Microscopic Colitis

What is microscopic colitis? — Microscopic colitis is a condition that causes watery diarrhea. It involves the colon, which is another name for the large intestine. There are 2 types of microscopic colitis: lymphocytic colitis and collagenous colitis. Both types cause the same symptoms and are treated the same way.

Microscopic colitis happens when the colon gets inflamed. But doctors don’t always know what makes the colon inflamed. In some cases, the condition seems to be caused by an infection in the digestive system. In other cases, it seems to be caused by medicines. For example, a group of medicines called nonsteroidal anti-inflammatory drugs, or “NSAIDs” for short, sometimes causes microscopic colitis.

Microscopic colitis happens most often in adults age 45 and older. Although the symptoms are bothersome, the condition is not life-threatening. It does not lead to serious problems, like cancer.

What are the symptoms of microscopic colitis? — Microscopic colitis causes episodes of diarrhea that is watery and not bloody. Most people have 4 to 9 watery bowel movements a day, but some people have more. Diarrhea can last weeks to months.

People sometimes have other symptoms, too. These commonly include weight loss, belly pain, or feeling very tired.

Is there a test for microscopic colitis? — Yes. Your doctor or nurse will do an exam and order different tests to exclude other causes of diarrhea and diagnose microscopic colitis. These can include:

Blood tests

Lab tests on a sample of your bowel movement

Colonoscopy – This is a procedure that lets the doctor look at the inside of your colon. The doctor will put a thin tube with a camera and light on the end into your anus and up into your rectum and colon. During a colonoscopy, the doctor will do a test called a biopsy. For a biopsy, he or she will take small samples of tissue from your colon. Then another doctor will look at the samples under a microscope to check for microscopic colitis. A biopsy is the only test that can tell for sure whether you have microscopic colitis.

How is microscopic colitis treated? — Treatment depends on your individual situation. It usually involves one or more of the following:

Medicine changes – If your doctor thinks that your symptoms are caused by a medicine you take, he or she will recommend that you stop taking that medicine.

Anti-diarrhea medicines, such as loperamide (brand name: Imodium) – These medicines reduce the number of bowel movements you have.

A steroid medicine called budesonide (brand name: Entocort) – This is different from the steroids athletes take to build muscle. This medicine helps reduce inflammation in the colon.

If these treatments don’t help enough to ease your symptoms, let your doctor or nurse know. There are other medicines or treatments that might help.

Some people need to be on treatment long term. That’s because symptoms sometimes come back after treatment is stopped.