Dr. Mark Yarwood Johnson is a Internal Medicine,General Physician and Gastroenterologist in Hillcrest, SAN DIEGO and has an experience of 53 years in these fields. Dr. Mark Yarwood Johnson practices at Scripps Mercy Hospital San Diego in Hillcrest, SAN DIEGO,Sharp Chula Vista Medical Center in Chula Vista 91911, Chula Vista CA and Scripps Mercy Hospital San Diego in San Diego 92103, SAN DIEGO. He completed Medical degree, DO from George Washington University School of Medicine in 1981,Residency in Internal Medicine from University of Southern California/Los Angeles General Medical Center in 1977 and Fellowship in Gastroenterology from University of California, Irvine in 1981. Some of the services provided by the doctor are: Esophageal Motility Disorders,Hepatitis B - Immune Response,Indigestion,Gastritis and Wireless pH Testing etc.