What Causes Hereditary Stomach Ailments?

Our family has a lot of stomach problems. By older brother has chronic colitis, my mother had a ruptured stomach also gallbladder desease. Nothing is helping my brother and he has been in a lot of pain. He just went thru a colonoscopy that showed he had a very bad case of colitis and did a barium test that didn t come up with anything new. Why has his pain increased? Are we missing another possible underlying problem?