Possible associations of dietary residues with growth of the large gut

Diets containing 67% cornstarch, or 42% cornstarch plus 25% lactose, agar, cellulose or raw potato starch, were fed to rats. Dimensions of the cecum and colon plus rectum and many characteristics of large intestinal and fecal residues were recorded. Possible relationships of these dimensions and characteristics to the diet-produced differences in weights of the cleaned cecum and colon plus rectum were sought by correlation and covariance methods. The following possible associations were found. The cecal dry weight was possibly associated with the length and maximum width of the cecum (containing its fill) and also with the weights of cecal fill. The dry weight and the weight:length ratio of the colon plus rectum were possibly associated with the fresh weight/fecal pellet and with other weights and dimensions of colonic fill and of feces. Despite these findings, in most cases we could not decide what relationship the residues might have to large intestinal growth and function. Nor could we decide how certain diets stimulate cecal or colonic growth.