IS COLONIC ELECTRICAL-ACTIVITY A SIMILAR PHENOMENA TO SMALL-BOWEL ELECTRICAL-ACTIVITY

PURPOSE: This study was designed to investigate colonic spike bursts r egarding 1) their migration behavior, 2) their pressure correlates, an d 3) comparing colonic short spike bursts with spike bursts from migra ting myoelectric complex from the small bowel. METHODS: Rectosigmoid e lectromyography and manometry were recorded simultaneously in seven no rmal volunteers and electromyography alone in five others during two h ours of fasting and for two hours after one 2,100-kJ meal. One patient with an ileostomy was also studied by the same method to record the m igrating myoelectric complex from the terminal ileum during fasting. R ESULTS: Three kinds of spike bursts were observed in the pelvic colon: rhythmic short spike bursts, migrating long spike bursts, and nonmigr ating long spike bursts. The meal significantly increased the number o f migrating and nonmigrating long spike bursts (from 25 to 38.7 percen t of the recording time; P < 0.01). These bursts of potentials showed a peak 15 minutes after the meal, which may be caused by the gastrocol ic reflex. Migrating long spike bursts started anywhere along the rect osigmoid and migrated from there aborad 82 percent of the time and ora d or in both directions in 10 or 7 percent of the time, respectively. They originated pressure waves 99 percent of the time. Short spike bur sts were more frequent before the meal (15.1 percent before and 9.6 pe rcent after the meal), but the difference was not significant; they ne ither propagated nor initiated pressure waves detected by the mini-bal loon. CONCLUSIONS: Migrating long spike bursts were the only potential s that migrated, sometimes for short distances. Short spike bursts are a different phenomenon from the small-bower migrating myoelectric com plex because they do not migrate; they can occur during the postprandi al period and never originated intraluminal pressure waves.