Intestinal resection leads to anatomo-physiological adaptive changes in the small bowel depending on its localization and extension. Two 50% resection models were done, jejunal resection (55 cm.) and ileal resection (55 cm.), in the attempt to determine the trophic response of the remnant bowel from jejunal and ileal samples. Significant increases were seen in mucosal villous length, jejunal values were greater than ileal and the greatest values were when the whole ileum was conserved. No significant changes were observed in DNA contents. These data suggest the importance of the ileal segment in the intestinal adaptive process, especially on the jejunal segment, as well as the apparent end of this response two weeks after resection.