Action potential bursts are localized within short regions of the structure , resulting in segmentation as the muscles contract in those regions. The ileocecal sphincter separates the ileum from the colon. Short-range peristalsis in the terminal ileum relaxes the sphincter allowing chyme to enter the colon. Opening and closing of the sphincter is controlled by the intramural plexuses. The longitudinal layer of the muscularis externa is formed into three bands, the taeniae coli.
Local contraction divide the colon into ovoid section called haustra.
Reverse peristalsis helps retain chyme in the proximal colon, facilitating absorption of water and salts. In the central and distal colon mass movement transfers the feces toward the rectum. Prior to defecation a mass movement fills the rectum, which is normally empty. This brings about a reflex relaxation of the internal anal sphincter and contraction of the external anal sphincter. Voluntary relaxation of the external sphincter will allow defecation to proceed.