This sounds like a very serious question. And it is. We don't know what causes inflammatory bowel disease (IBD). The theory right now is that IBD is caused by a combination of genetics and environment. You might carry the gene, and then something (or a combination of somethings) happens that flips the switch and turns on the IBD.

For me, IBD really runs in my family. I had a mysterious rash one year that we suspected was Lyme disease. I had spent the summer doing local "clean-ups" and had spent a fair amount of time running around in rivers, streams, fields, and wooded areas, so it was not an unreasonable suspicion. I was treated for suspected Lyme disease with antibiotics, and the next thing I knew, the symptoms of ulcerative colitis had set in. I'll never know for sure what exactly caused my IBD, but it does seem as if the events of that summer had something to do with it.

How about you? What caused your IBD? Does it run in your family? Did you get diagnosed after a stressful event? Use the "comment" button below to tell me about it.

• The Epidemiology of IBD
• Know Your IBD History
• Does Stress Cause IBD?