Depending on the type of endoscopy performed, doctors can see different organs. For instance, during an upper endoscopy, medical professionals can examine the esophagus, stomach, and the beginning of the small intestine (duodenum). Upper endoscopies are useful for diagnosing conditions like ulcers, GERD, esophageal varices, upper GI tract infections, and tumors.   Another common endoscopic procedure that gastroenterologists perform is colonoscopy. In this procedure, medical professionals can view the entire colon (large intestine) and rectum, which allows them to detect colorectal cancer, polyps, and inflammatory bowel diseases.   Sigmoidoscopy is similar to colonoscopy, but it focuses on the lower part of the colon and rectum, specifically the sigmoid colon. This procedure is often used to screen for colorectal cancer and investigate the cause of rectal bleeding.   Your doctor will assess your symptoms to determine which type of endoscopy is needed to diagnose your discomfort. Whether you need an upper endoscopy, colonoscopy, or sigmoidoscopy, the specialists at Advanced Gastroenterology of Central Florida provide top-quality care.