The function of the digestive system is to break down the foods you eat, release their nutrients, and absorb those nutrients into the body. The digestive system is continually at work, yet people seldom appreciate the complex tasks it performs until something malfunctions. Consider what happens when you eat an apple. You enjoy the apple’s taste as you chew it, but in the hours that follow, unless something goes amiss and you get a stomachache, you don’t notice your digestive system is working. You may be working, studying, or sleeping, having forgotten all about the apple, but your stomach and intestines are busy digesting it. By the time any waste material is excreted, the body has absorbed all the nutrients it can use from the apple. In short, whether you pay attention or not, the organs of the digestive system perform their specific functions, allowing you to use the food you eat to provide energy for your daily activities.^[1]

This chapter will review common word components related to the digestive system to assist learners in analyzing, building, and defining medical terms. Other terms, whose definitions cannot be easily built from word components, will be described in context based on the anatomy and physiology of the digestive system and common diseases and disorders. Medical specialists, diagnostic tests, and procedures related to the digestive system will also be discussed.