Skip to main content
Provider facility background
Barrett J Wallis, MD

Barrett J Wallis, MD

Gastroenterology
B. Jeffrey Wallis, MD is Board Certified in Internal Medicine and Gastroenterology, and received his medical degree from the Joan Sanford I Weill Medical College of Cornell University in 1979. Dr. Wallis specializes in gastroenterology at Oak Hill Hospital, providing diagnostic and therapeutic management of digestive disease and liver disorders with the most advanced diagnostic and treatment methods for colorectal cancer, heartburn and reflux disease, hiatal hernia, swallowing difficulties, irritable bowel, change in bowel habits, constipation, diarrhea, hemorrhoids, ulcers, colitis, diverticulitis, abdominal pain, liver and gallbladder problems and much more. Dr. Wallis is a practicing gastroenterologist and hepatologist at Advanced Gastroenterology in Crystal River, Florida. He performs procedures including capsule enteroscopy, colonoscopy, colorectal cancer screening, chron's disease, ERCP, endoscopic ultrasound, esophageal manometry, flexible sigmoidoscopy, gastroscopy, nutritional therapy, and virtual colonoscopy.
  • Gastroenterology - Primary - Board Certified
  • Graduate Degree: Cornell University Medical College
  • Fellowship: State University of New York - Stonybrook
  • Residency: University of Michigan
  • English
  • Citrus Memorial Hospital
  • Oak Hill Hospital