What causes the pain that comes with ibs? I can understand how there is pain in ibs that is caused by a food intolerance because there will probably be some physical damage/inflammation. But if the ibs is caused by bacteria imbalance why is there pain, is it gas. Also how do you know if you have gas, would you pass wind a lot? I am not sure if I have gas or if i have a damaged inflamed gut all I know is that my stomach is tender when pressure put on it.