A gastroenterologist is a doctor who specializes in diagnosis and treatment of diseases and disorders associated to the digestive system. Gastroenterologists specialize in the medical treatment of gastrointestinal tract diseases from mouth to anus including stomach, intestines and liver. A gastroenterologist is qualified to provide medical treatment for diseases like gastric disorders, pancreatitis, biliary tract disease, achalasia, hepatitis, acid reflux, gallbladder stones and irritable bowel syndrome.