Abstract
Subtotal colectomy with ileo-proctostomy is followed by severe diarrhea which gradually subsides without treatment over a three to four month period. The mechanism of adaptation was studied in the dog. So morphological changes of the ileal mucosa were observed before, 1 week, 4 weeks, 12 weeks, 40 weeks following subtotal colectomy in 50 dogs. With light microscopic measurement average ileal villus length increased since 4 weeks, and the number of mucosal cells from crypt to tip of villus increased since 12 weeks. These finding shows that ileal absorptive surface increases after subtotal colectomy. Scanning electron microscope showed that ileal villi progressively changed from finger shape to tongue since 4 weeks, but ileal villi density was not changed postoperatively. Transmission electron microscope showed that the microvilli on the ileal mucosal cell did not change postoperatively, however 48 weeks after subtotal colectomy, the enteric surface coat over the microvilli developed thicker.
