Early postoperative small bowel obstruction is a rare (0.69 percent incidence) but serious postoperative complication with a relatively high mortality rate (17.8 percent). Operations performed below the transverse mesocolon impose an increased risk, whereas those limited to the upper abdomen are virtually free of risk. The clinical picture of a patient who initially manifests a return of gut function and advances to a diet, but then has loss of bowel function with distention and pain is most characteristic of early postoperative small bowel obstruction. Any patient in the high-risk group demonstrating this clinical picture should be presumed to have a mechanical small bowel obstruction, and early operation should be considered.