We recommend Bowel Motion and Intestinal Cleanser for Irritable Bowel Syndrome. The Colon Cleanse can also be very beneficial. It's possible for one to have a reaction to Milk Thistle, but more often than not, it's a healing crisis, as the herb is deeply cleansing the body, esp. the liver. Herbs shouldn't harm, they simply help to heal.

Bowel Motion
Intestinal Cleanser
10 Day Colon Cleanse