• Absorption
• Achalasia
• Acute appendicitis
• Acute mesenteric ischemia
• Acute pancreatitis
• Alcoholic hepatitis
• Alcoholic liver disease
• Angiodysplasia
• Antiemetics
• Atrophic gastritis
• Budd-Chiari syndrome
• Celiac disease
• Choledocholithiasis
• Cholelithiasis
• Chronic pancreatitis
• Cirrhosis
• Colonic polyps
• Colorectal cancer
• Congenital neck masses
• Crohn disease
• Diarrhea
• Dieulafoy lesion
• Diverticulosis
• Eosinophilic esophagitis
• Erosive gastritis
• Esophageal cancer
• Esophageal diverticula
• Esophageal hypermotility disorders
• Gallstones
• Gastric cancer
• Gastrinoma
• Gastroesophageal reflux disease
• Gastroschisis
• GI hormones
• Halothane hepatitis
• Hepatitis B
• Hepatitis A
• Hepatitis C
• Hepatocellular carcinoma
• Hepatomegaly
• Hiatal hernia
• Hirschsprung disease
• Intestinal atresia
• Intraperitoneal and extraperitoneal abdominal structures
• Intrinsic factor
• Lactose intolerance
• Irritable bowel syndrome
• Lynch syndrome
• Liver zones
• Malabsorption
• Mallory-Weiss syndrome
• Malrotation
• MALT lymphoma
• Medication-induced esophagitis
• Mirizzi syndrome
• Ménétrier disease
• Nonalcoholic fatty liver disease
• Pancreatic cancer
• Pectinate line
• Peptic ulcer disease
• Plummer-Vinson syndrome
• Primary biliary cholangitis
• Primary sclerosing cholangitis
• Proton pump inhibitors
• Stomach histology
• Steatorrhea
• Toxic megacolon
• Stool osmotic gap
• Warthin tumor
• Ulcerative colitis
• Wilson disease
• Whipple disease