A possible explanation for postoperative diarrhea after colostomy closure.

The transient diarrhea that sometimes follows the closure of colostomies has been ascribed to rapid transit in the previously defunctionalized distal colon. However, the present study of the temporarily bypassed colon in the rat indicated that a reduced capacity for the absorption of sodium and water develops within two to three weeks after bypass, without significant decreases in transit time or colon volume. After restoration of continuity, the absorptive capacity for water increased to normal under some of the experimental conditions. It is therefore suggested that postoperative diarrhea after colostomy closure in man may be related to a temporary decrease in absorptive capacity in the previously bypassed distal colon.