DEAR DOCTOR K: I have irritable bowel syndrome. Can you explain what has caused it?
DEAR READER: The honest answer is we don't know what causes irritable bowel syndrome (IBS). Over the past 20 years, we've discovered some clues and developed some new treatments. IBS is a common condition. Symptoms include abdominal pain, diarrhea and/or constipation, bloating, gassiness and cramping. Here is the criteria that doctors look for when diagnosing IBS: