Dr. John M. Lyons is a gastroenterologist in San Diego, California and is affiliated with Scripps Green Hospital. He received his medical degree from University of Southern California School of Medicine and has been in practice for more than 20 years. Dr. John M. Lyons has expertise in treating colonoscopy, upper gi endoscopy, inflammatory bowel disease (ibd), among other conditions - see all areas of expertise. Dr. John M. Lyons accepts Medicare, Aetna, Blue Cross, United Healthcare - see other insurance plans accepted.