Many people believe that too much gas causes abdominal bloating. However, people who complain of bloating often have normal amounts and distribution of gas. They may just be unusually aware of gas in the digestive tract.
Doctors believe that bloating is usually the result of an intestinal disorder, such as irritable bowel syndrome (IBS). The cause of IBS is unknown, but may involve abnormal movements and contractions of intestinal muscles and increased pain sensitivity in the intestines. These disorders may give a sensation of bloating because of increased sensitivity to gas.
Any disease that causes intestinal inflammation or obstruction, such as Crohn?s disease or colon cancer, may also cause abdominal bloating. In addition, people who have had many operations, internal hernias, or bands of internal scar tissue called adhesions, may experience bloating or pain. Finally, eating a lot of fatty food can delay stomach emptying and cause bloating and discomfort, but not necessarily too much gas.This answer is based on the source infromation from the National Institute of Diabetes and Digestive and Kidney Diseases.