The gastroenterologist treats patients with not only gastrointestinal disorders (from esophagus to stomach and intestines), but also conditions of the liver gallbladder, and pancreas. The gastroenterologist sees medical imaging studies (such as CT/MRI but also contrast studies of the intestines and bowels) and performs procedures such as endoscopy (upper gastrointestinal tract) and colonoscopy (lower gastrointestinal tract). Common diseases include peptic ulcer, gastritis, gastro esophageal reflux, gastrointestinal bleeding, hepatitis, various types of malabsorption syndromes as well as inflammatory bowel diseases (ulcerative colitis and Crohn’s disease) and cancers. In children, diseases include feeding and/or nutritional disorders (including reflux and food intolerances), liver disorders, and diarrhea/constipation.