Migrating motor complex

Migrating motor complex, also known as migrating myoelectric complex, migratory motor complex, migratory myoelectric complex and MMC, is a cyclic, recurring motility pattern that occurs in the stomach and small bowel during fasting; it is interrupted by feeding.^[1] A pattern of electrical activity is also observed in the gastrointestinal tract in a regular cycle during this interdigestive period.

MMC was discovered and characterized in fasting dogs in 1969 by Dr. Joseph H. Szurszewski at the Mayo Clinic.^[2] He also showed that this activity stops upon eating a meal, and suggested that it induces a motor activity that acts as an "interdigestive housekeeper" in the small intestine.^[2] These motor complexes trigger peristaltic waves, which facilitate transportation of indigestible substances such as bone, fiber, and foreign bodies from the stomach, through the small intestine, past the ileocecal sphincter, and into the colon. MMC activity varies widely across individuals and within an individual when measured on different days. The MMC occurs every 90–230 minutes during the interdigestive phase (i.e., between meals) and is responsible for the rumbling experienced when hungry.^[3][4] It also serves to transport bacteria from the small intestine to the large intestine and to inhibit the migration of colonic bacteria into the terminal ileum; an impairment to the MMC typically results in small intestinal bacterial overgrowth.^[5]