Suggest Remedy For Irritable Bowel Syndrome

My seven years old son suffered with accute pneumonia, along with mild hepto spleeno megale in December09. after pneumonia treatment he was under meditation for two months for liver care. After he became completely alright I started giving non veg. food. After two weeks he developed irregular bowl syndrome. Now I stoped non veg food but IBS is still continuing since 20-25 days. please suggest!