Metabolism of body water and electrolytes after surgery for ulcerative colitis: conventional ileostomy versus J pouch.

Some authorities believe that patients with conventional ileostomies are chronically water and salt depleted but there are no data on the metabolism of body water and electrolytes after ileoanal J pouch. To clarify the situation we studied the body composition of 14 patients with well functioning ileostomies and 20 patients with well functioning J pouches. Both groups were compared with two closely matched control groups. Body weight, total body fat, fat-free mass, total body water and extracellular water were measured by neutron activation analysis, tritiated water and bromide dilution respectively; 24-h collections of urine and stool were analysed for volume and electrolyte content. The results show that the body content of water and extracellular fluid in ileostomy patients and J pouch patients is normal. The faecal volume and chemistry is similar in both groups resulting in a similar and significant degree of urinary sodium retention.