Endoscopy
No other internal medicine field is as associated with imaging as gastroenterology, and a wide variety of options exist to visualize, sample, and treat the GI tract, pancreas, liver, and biliary tree.
Upper Endoscopy
Upper endoscopy, or esophagogastroduodenoscopy, allows visualization to the third or fourth portion of the duodenum. It may be used for visualization, treatment of esophageal varices or upper GI bleeding, removal or ablation of malignancy, and placement of stents.
Barrett's esophagus
Can treat strictures, take biopsies, mucosal ablation
Fairly well tolerated
Enteroscopy
Enteroscopy can be used to visualize the entire small intestine, either by mouth, through surgical entry, or by combining anterograde and retrograde approaches.
Sigmoidoscopy and Colonoscopy
Flexible sigmoidoscopy allows visualization up to the splenic flexture and is a convenient tool for colorectal cancer screening. Enemas are given beforehand, the procedure takes less than 10 minutes, and sedation is typically not needed. Sigmoidoscopy can also be used to evaluate diarrhea, hemorrhage, and resopse to colitis treatment. The colon does not have any pain receptors. Rather, it is the air pumped in, or navigating corners, which activated stretch receptors.
Colonoscopy allows visualization of the entire colon and several centimenters of the ileum. Bowel cleansing is required. As it can be uncomfortable, sedation is often used. Colonoscopy can be used to evaluate iron deficiency anemia and blood loss, assess inflammatory bowel disease, and screen for dysplasia or malignancy. Many therapeutic options are also provided by colonoscopy.
Endoscopic Retrograde Cholangiopancreatography
Endoscopic Retrograde Cholangiopancreatography (ERCP) combines endoscopic and radiographic procedures to visualize the biliary and pancreatic ducts.