The digestion and absorption from the small bowel of the carbohydrate of banana has been studied by feeding ileostomy subjects banana from six batches of different ripeness and measuring the amounts excreted in the effluent. Starch content of bananas depended on the ripeness being 37% of dry weight in the least ripe and 3% in the most ripe. Excretion of carbohydrate from banana in ileostomy effluent ranged from 4-19 g/day and was directly related to the starch content (r = 0.99). Up to 90% of the starch could be accounted for in the effluent. Complete recovery of nonstarch polysaccharides [NSP (dietary fiber)] was obtained. The amount of banana starch not hydrolyzed and absorbed from the human small intestine and therefore passing into the colon may be up to 8 times more than the NSP present in this food and depends on the state of ripeness when the fruit is eaten.