Stomach There are many different stomach problems: gastritis or gastric ulcers, functional gastric disorders or gastric cancer. Small Intestine The small intestine is divided into three sections. Diverticula, ulcers or polyps can cause problems throughout the small intestine. Colon Diseases of the intestine include colon polyps, colon cancer, diverticular disease, colonic inflammation or functional bowel disorders. Oesophagus Unpleasant pain in the oesophagus, for example, can be caused by a reflux disorder or by oesophageal cancer.