Morphologic and functional adaptations of large bowel after small-bowel resection in the rat

Seventy percent small bowel was resected in rats. Two and four weeks later transport of sodium, chloride, and water was examined in cecum and more distal large bowel (colon) using a well-established in vivo luminal perfusion technique. Sham-operated and unoperated rats served as controls. In cecum mucosa grew 29% by two weeks after resection but transport remained unchanged. There were no further adaptive changes by four weeks after resection. Unexpectedly, cecum of all rats secreted water and electrolytes. The mechanism remains unclear. In colon there were no adaptive changes by two weeks after resection but by four weeks colon mucosa increased 14% and luminal absorption increased proportionately. Separate studies showed hexose transport could not be induced in cecum or colon, although we have previously demonstrated its induction in contiguous remnant ileum.