Medial fossa

The medial fossae are concave depressions of peritoneum in the paravesical space bounded by the medial umbilical folds and the lateral umbilical folds. The fossae are contained within the inguinal (Hesselbach’s) triangle. The right medial fossa typically partially contains the cecum and/or ileum and the left medial fossa partially contains the sigmoid colon. These abdominal structures can be displaced by ascites.

The medial fossa is the origin of most direct inguinal hernias.