William E. Karnes, MD

Dr. William E. Karnes is a board-certified UCI Health gastroenterologist who specializes in disorders of the gastrointestinal tract, including colorectal cancer screening, gastrointestinal reflux disease (GERD), swallowing disorders, irritable bowel syndrome, peptic ulcers and esophageal disorders. He performs colonoscopies, upper endoscopies and capsule endoscopies, and treats gastrointestinal bleeding, chronic diarrhea, constipation, bloating and bacterial problems in the small intestines. Karnes earned his medical degree from the University of Minnesota Medical School in Minneapolis, where he completed a residency in internal medicine. He went on to complete a fellowship in molecular biology at Mayo Clinic in Rochester, Minn., and a fellowship in gastroenterology at the University of California, Los Angeles. His research interests include colon cancer screening, risk assessment for colon cancer and artificial intelligence-assisted colonoscopy. He also conducts translational research on colon cancer prevention, with an emphasis on regular colorectal screening, especially among patients and families with a genetic risk for developing the disease.