Ileocecal valve, as the name indicates, is a structure present at the junction of ileum and cecum. It is a rudimentary valve and consists of two horizontal folds of mucous membrane that project around the opening of the ileum.
The ileocecal valve plays little or no role in prevention of reflux of cecal contents into the ileum. Instead the circular muscle of the lower end of the ileum (commonly known as the ileocecal sphincter) serves as the actual sphincter to control the flow of contents from ileum into the large intestine.
The tone of this smooth muscle sphincter is reflexly increased when the cecum becomes distended. This prevents any reflux of cecal material into the ileum. On the other hand, the hormone Gastrin, which is produced by the stomach, causes relaxation of this sphincter and thus allows passage of food from ileum to cecum.