When you see, smell or ingest food, the stomach relaxes so that it can store the bulk of the food for many hours. Hydrochloric acid and a variety of digestive enzymes are secreted in the stomach. These help break down the food into smaller pieces which can be more readily digested. In addition to this, the lower portion of the stomach, called the antrum, has a grinding function which also helps mechanically break down the food into smaller pieces. Another function of the stomach, is to act as a kind of sterilizing system, where the stomach acids kill germs in food.
T here are several disorders which can occur in the stomach.
Peptic ulcers are discussed here. Links to other sites which discuss stomach cancer are found below.