Microscopic Colitis

What is microscopic colitis?

Microscopic colitis includes collagenous colitis and lymphocytic colitis and is characterized by chronic diarrhea caused by inflammation in the colon. Collagenous colitis and lymphocytic colitis are two types of bowel inflammation that affect the colon (large intestine). They are not related to Crohns disease or ulcerative colitis, which are more severe forms of inflammatory bowel disease (IBD). These conditions are not life-threatening and there is no increased risk of cancer.

This condition is known as "microscopic" colitis because physicians can't see the inflammation without a microscope. Instead, tissue samples from the colon must be examined under a microscope to make the diagnosis. When looked at through an endoscope during a colonoscopy or sigmoidoscopy, the colon appears entirely normal.

What causes microscopic colitis?

The exact cause of collagenous colitis or lymphocytic colitis is unknown. There is a strong association with a wide variety of medications, especially non-steroidal anti-inflammatory drugs (NSAIDs). You should carefully review all of your medications with a gastroenterologist to see if there is an association with microscopic colitis.

What are the symptoms of microscopic colitis?

The symptoms of collagenous colitis and lymphocytic colitis are similar--chronic watery, non-bloody diarrhea. The diarrhea may be continuous or episodic. Abdominal pain or cramps may also be present.

How is microscopic colitis treated?

Treatment for collagenous colitis and lymphocytic colitis varies depending on the symptoms and severity of the cases. The diseases have been known to resolve spontaneously, but most patients have recurrent symptoms.

When possible, it is a good idea to start with avoiding potentially offending medications. You should speak with your provider before discontinuing any medications, as some should not be stopped suddenly.

Some patients benefit from the use of antidiarrheal agents, Imodium and Lomotil. However, many patients require medicines, such as budesonide (Entocort), bismuth subsalicylate (PeptoBismol), or mesalamine (Asacol). Stronger medications, such as immunosuppressants, are rarely necessary.