General surgery is a surgical specialty that focuses on abdominal contents including esophagus, stomach, small intestine, large intestine, liver, pancreas, gallbladder, appendix and bile ducts, and often the thyroid gland (depending on local referral patterns).
You may call them simply doctors. But most doctors have extra expertise in one type of medicine or another. In fact, there are several hundred medical specialties and subspecialties. Here are the most common types of doctors you'll likely see.