[24 hours of intestinal motility]

The normal pattern of fasting motility in the small intestine shows migrating bursts of intense electrical activity associated with smooth muscle contractions. The migrating motor complex (MMC) is a recurring pattern of contractions of the human small bowel which is inhibited in the fed state. At any given site the entire MMC cycle comprises three phases numbered 1, 2 and 3. Phase 3 activity, the most prominent feature of the MMC, consists of a burst of intense contractions which generally start in the stomach or in the duodenum and migrate distally. In humans, phase 3 recurs every 110 minutes and clears the small bowel of cellular debris and residual food. During phase 2, several other patterns of motility have been identified in man. The migrating action potential complex (MAPC) or its manometric equivalent (peristaltic rush) is an infrequent event in normal subjects, occurring only once every 160 minutes. Minute rhythms are defined as rhythmic bursts of phasic contractions of shorter duration than phase 3 and occurring with a much greater periodicity. They never occur in fed state. At night, the periodicity of phase 3 is more regular and its propagation velocity is slower than during daytime. In normal subjects the MMC pattern shows important inter- and intra-individual variations which need to be known to study patients with disorders of small bowel motility.