Large bowel growth.

Developmental events in the large bowel have been studied pre- and post-natally and indicate that by birth, crypt organisation and kinetic activity are organised along adult lines. The period from birth to maturity is marked by an increase in crypt size and a massive increase in their number, with new crypts developing by a process of longitudinal fission from the base of existing ones. We know little of the fate of crypt size and number thereafter. Adaptive responses to resection or bypass of intestine are much less marked in large bowel when compared to small bowel, but in general postoperative responses have not been as extensively examined. Of the factors maintaining mass and cell turnover in large bowel mucosa simple luminal bulk seems to be most important, although a role exists for endocrine and neurovascular influences. Knowledge of growth, kinetic activity and adaptive responses in human large bowel is scanty and represents a large area for further study.