Dr.Sowerby graduated from Charing Cross and Westminster Medical School, University of London, England in 1987. He completed pre-registration house officer appointments (internships) in general surgery and medicine at the Queen Elizabeth Hospital, Kings Lynn and the West Middlesex University Hospital, London respectively. These were followed by senior house office appointments in family practice and medicine at Queen Elizabeth Hospital, Kings Lynn. In 1990 he moved to California. After a residency in internal medicine at Kaiser Foundation Hospital, San Francisco he completed a fellowship in gastroenterology Kaiser Foundation Hospital, Los Angeles. From 1995 to 2000 he was a member of the Permanente Medical Group practicing gastroenterology in both San Francisco and San Rafael. In 2000, Dr. Sowerby entered private practice in Marin County. Dr. Sowerby. is Board Certified in Gastroenterology.