It may temporarily become partially or completely shut off from the remainder of the stomach during digestion by peristaltic contraction of the prepyloric sphincter; it is demarcated, sometimes, from the pyloric canal by a slight groove.

The pyloric canal (Latin: canalis pyloricus) is the opening between the stomach and the duodenum.

It acts as a valve, controlling the outflow of gastric contents into the duodenum[6] and release of chyme.

Under microscopy, the pylorus contains numerous glands, including gastric pits, which constitute about half the depth of the pyloric mucosa.

The pylorus, through the pyloric sphincter, regulates entry of food from the stomach into the duodenum.

In such conditions as stomach cancer, tumours may partly block the pyloric canal.

A special tube can be implanted surgically to connect the stomach to the duodenum so as to facilitate the passage of food from one to the other.