If milk and other dairy products bother you, you may have lactose intolerance. Lactose intolerance means that your body can't digest lactose (the sugar in milk).
Dairy products may seem to make IBS symptoms worse if you're lactose intolerant. If this seems to be the case, you may need to limit the amount of milk and milk products in your diet. Talk to your family doctor if you think you have trouble digesting dairy products.