The stomach is an organ located in the alimentary canal. Its job is often confused with that of the intestine. Our stomach is not responsible for absorbing nutrients from digested food like the intestine is. Its primary function is to quite simply digest whatever it is that we decide to eat.

Located between the esophagus and the first part of the small intestine, the stomach is a highly acidic environment containing many digestive enzymes. The interior of the stomach is able to secrete about 2 to 3 litres of gastric fluid every day. It is a large organ that is multichambered, and hosts bacteria which produce the necessary enzymes for the digestion of cellulose from plant matter. The stomach will regurgitate and rechew plant matter at least once during the digestion process of sequentially passing food through the stomach's chambers.

Stomach's are divided into five sections, each of which having different functions and cells. Gastric juice in the stomach keeps a pH level anywhere between 1 and 3. The pH scale is a way of determining how acidic a substance is. The larger the pH level, the less acidic a substance is. Sometimes the highly acidic gastric juice eats away at the stomach wall or its layer of mucus, causing what is called an "ulcer".

Common diseases that occur in the stomach are a Curling ulcer, Cushing ulcer, Stomach cancer, Gastritis, Linitis plastica, Peptic ulcer, Zollinger-Ellison syndrome, Cardia, Gastric acid, Gastric distention, Monogastric, Nasogastric tube, Peptic ulcer, Stomach ache, Stomach cancer, and Borborygmi. "Gastric-" or "Gastro-" are latin names for the stomach, which are commonly used in any medical term concerning this organ.