Gastroenterology is the specialty that focuses on digestive health, an important component of overall health. Gastroenterologists specialize in conditions that affect the digestive system, that is, the esophagus, stomach, intestines, liver, gallbladder, and other related organs. They treat conditions such as heartburn, ulcers, jaundice, gallstones, irritable bowel syndrome (IBS), diverticulitis, and cancer. Gastroenterologists know how effective colonoscopy is as a screening tool for colorectal cancer. When colon cancer is detected early, it is usually extremely treatable. Initial colonoscopies are recommended for most men and women beginning at age 50.