All patients with the diagnosis of acute colonic pseudoobstruction at the University of California, Davis Medical Center from 1979-1985 were reviewed. These 25 patients were initially treated conservatively (nasogastric tube/rectal tube/enemas) and this was successful in eight of 25 patients (32%). The remaining 17 patients (68%) unresponsive to conservative therapy received endoscopic intervention, either colonoscopic suction decompression (CSD) or colonic suction decompression with proximal colonic tube placement (CDT) for continuous decompression. Of the endoscopic procedures performed, 13/17 (76%) resulted in successful acute decompression. Recurrences occurred in 6/13 (45%) (3/7 in the colonoscopic suction decompression group and three of six in the colonic tube placement group). In the 10 failures, six further procedures were attempted, but only one was successful. These patients were then treated conservatively. There were no instances of colonic perforation. Acute pseudoobstruction in our experience is a benign entity that can be safely and successfully treated nonsurgically. Colonoscopic suction decompression is often initially successful but has a high frequency of recurrence. Newer techniques to prevent recurrence, i.e., colonic tube placement, are of potential benefit but presently have technical problems.