Risk factors for microscopic colitis include:

  • Age and gender. Microscopic colitis is most common in people ages 50 to 70 and more common in women than men.
  • Immune system problems. People with microscopic colitis sometimes also have an autoimmune disorder, such as celiac disease, thyroid disease or rheumatoid arthritis.
  • Smoking. Recent research studies have shown an association between tobacco smoking and microscopic colitis, especially in people ages 16 to 44.

Some research studies indicate that using certain medications may increase your risk of microscopic colitis. But not all studies agree. Medications linked to the condition include:

  • Aspirin, acetaminophen (Tylenol, others), and ibuprofen (Advil, Motrin IB, others)
  • Proton pump inhibitors, including lansoprazole
  • Acarbose (Precose)
  • Flutamide
  • Ranitidine (Zantac)
  • Selective serotonin reuptake inhibitors, such as sertraline (Zoloft)
  • Carbamazepine

It's not clear why some people who use these medications develop microscopic colitis while others don't.

Jan. 30, 2013