Small bowel function after surgery for chronic radiation enteritis.

The retention of the gamma-emitting 75Se-homotaurocholic acid (SeHCAT) after 72 and 168 h was assessed in 10 patients after ileal resection for radiation injury (group I). 6 patients suffering from chronic postirradiation diarrhea (group II) and 6 patients in whom the ileum had been resected for other indications (group III) were also examined. The retention of SeHCAT was abnormally low (less than 50%) in all cases after 72 h and below 20% in 19 out of 21 cases after 168 h. The length of resected small bowel (groups I and III) was inversely related with SeHCAT retention after 72 h (r = 0.63; p = 0.015), but not after 168 h. There was no correlation between the diarrhea score and the extent of bowel resection, SeHCAT retention or xylose absorption. Hydrogen breath test with lactulose revealed a significantly shortened orocecal transit time in group I, compared to groups II and III. Xylose absorption was significantly reduced in patients with positive 5 g xylose-H2 breath test. In groups I and III, however, xylose absorption tended to improve with increasing time interval following resection (r = 0.79; p = 0.003). It is concluded that radiation injury in addition to small-bowel resection contributes significantly to malabsorption and diarrhea in patients after ileal resection for radiation sequelae. The chronic radiation damage seems to act mainly through impaired motility.