The colon influences ileal resection diarrhea.

Fecal mass and electrolyte concentrations from 25 ileectomy and/or colectomy patients on known diets were used to assess those factors most responsible for their diarrhea. In 18 ileectomy patients the severity of diarrhea, expressed as a fecal weight, was a function of both percent of colon and centimeters of ileum removed. Linear regression analysis, however, showed that the extent of missing colon had three times the effect of missing ileum on fecal weight. Patients who lost the ileocecal valve and part of the right colon had more diarrhea than those who lost comparable lengths of ileum but had this area preserved. Fecal ion concentrations seemed independent of diet but were related to fecal weight and the amount of colon and ileum removed. Potassium concentration was strongly dependent on the amount of colon lost, while sodium concentration was more influenced by the length of resected ileum. Choloride was most dependent on fecal weight. As expected, fecal fat correlated strongly with the extent of ileum removed. Regresison equations were constructed from the electrolyte data which described and predicted the extent of lost ileum or colon. Our data were also used to separate patients with less than 100 cm of ileum removed from those with more extensive resections. The severity of diarrhea following ileal resection depends primarily on the amount of contiguous colon removed. Varying loss of ileum and colon produced predictable effects on fecal weight and electrolyte composition. Surgeons should preserve the maximum amount of colon possible to reduce the severity of diarrhea in these patients.