The ileocecal valve (ileal papilla, ileocaecal valve, Tulp's valve, Tulpius valve, Bauhin's valve, ileocecal eminence, valve of Varolius or colic valve) is a

sphincter muscle A sphincter is a circular muscle that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning. Sphincters are found in many animals. There are over 60 types in the hu ...

valve that separates the

small intestine The small intestine or small bowel is an organ in the gastrointestinal tract where most of the absorption of nutrients from food takes place. It lies between the stomach and large intestine, and receives bile and pancreatic juice through t ...

and the

large intestine The large intestine, also known as the large bowel, is the last part of the gastrointestinal tract and of the digestive system in tetrapods. Water is absorbed here and the remaining waste material is stored in the rectum as feces before being r ...

. Its critical function is to limit the reflux of colonic contents into the

ileum The ileum () is the final section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms posterior intestine or distal intestine m ...

. Approximately two liters of fluid enters the colon daily through the ileocecal valve.

Microanatomy

The

histology Histology, also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures vi ...

of the ileocecal valve shows an abrupt change from a villous mucosa pattern of the ileum to a more colonic mucosa. A thickening of the

muscularis mucosa The lamina muscularis mucosae (or muscularis mucosae) is a thin layer ( lamina) of muscle of the gastrointestinal tract, located outside the lamina propria, and separating it from the submucosa. It is present in a continuous fashion from the eso ...

, which is the

smooth muscle Smooth muscle is an involuntary non- striated muscle, so-called because it has no sarcomeres and therefore no striations (''bands'' or ''stripes''). It is divided into two subgroups, single-unit and multiunit smooth muscle. Within single-unit ...

tissue found beneath the mucosal layer of the