Total colectomy with ileorectal anastomosis in the cat

Total colectomy with end-to-end ileorectal anastomosis was performed in eight healthy adult cats. Hydration status, body weight, attitude, appetite, and stool consistency were monitored for 24 weeks. Ileal water absorption was determined at weeks 1, 6, 12, 18, and 24 using the double-lumen catheter intestinal perfusion technique with polyethylene glycol as the indicator substance. Bowel adaptation was evaluated by histologic morphometric analysis of full-thickness ileal biopsies taken at the time of total colectomy and at weeks 6, 12, 18, and 24. The anastomoses were examined at necropsy for evidence of leakage and development of strictures. All cats resumed normal activity in 48 hours and maintained or gained weight during the study. Small volumes of watery diarrhea were present immediately after surgery, but by week 1 all cats had a semi-solid nonformed stool. At month 2, three cats developed semi-solid formed stools. One cat had occasional perineal soiling and five cats had at least one episode of hematochezia. There was improvement in ileal water absorption in two cats, and there were significant increases in villus height, enterocyte height, and enterocyte density in all cats. Results of postmortem examination of the anastomosis showed no evidence of stricture in any cat.