I'm going with the other, because mine was never diagnosed. After my last surgery, I had occasional times under abdominal stress (exercise), that I had a "popping" feeling happen where the stoma had been. There was a large, very hard bump visible, and it was really painful. It reduced with a little pressure, but thought I might have needed a trip to the hospital if it lasted longer. Haven't had it back for several years though, so I think I have tightened up my abs a little.