Abdominal pain, bloating, and gas can be caused by any number of problems, but diverticulitis is a common source of those symptoms. It is an infection of the large intestine that can cause mild to severe pain, particularly in the lower left part of the abdomen. Tom Miller, MD, and Bartley Pickron, MD, discuss when you should see your physician and what they can do to treat the infection and alleviate your pain.