Postoperative electrolyte and mineral balance after restorative proctocolectomy with ileoanal reservoir.

: Postoperative electrolyte and mineral balance was studied in nine patients with ulcerative colitis who underwent restorative proctocolectomy with ileoanal reservoir (J-pouch). The study was carried out during the first seven days of bowel function after construction of the reservoir and temporary ileostomy, and again after the ileostomy was closed and bowel continuity re-established. Stool volume and intestinal sodium excretion were reduced by respectively 40 and 45% after ileostomy was closed (p < 0.05), but potassium excretion was unchanged. The concentration of sodium was higher in ileostomy effluents, whereas the concentration of potassium was higher in stools after the ileostomy was closed (p < 0.05). Significant changes in blood and urinary electrolytes or minerals were not recorded. It is concluded that a major reduction in stool volume and intestinal excretion of sodium is already present in the early postoperative period after bowel continuity has been re-established.