A professor of medicine, Dr. Geoffrey Turnbull is a gastroenterologist and a GI motility expert. In his practice, he sees patients who suffer from irritable bowel syndrome alongside other disorders. In 1998 he co-authored IBS Relief: A Complete Approach to Managing Irritable Bowel Syndrome, which is still considered the definitive patient guide to the disorder.

Dr. Turnbull is a prolific researcher whose extensive research in gastrointestinal motility disorder has made him a world expert in irritable bowel syndrome. His work has been published in many of the world’s top medical journals.