Malabsorption of bile salts plays a major role in the pathogenesis of diarrhea after resection of the ileum, but the diarrhea usually improves with the passage of time. To test the hypothesis that this improvement may occur as a result of increased absorptive capacity for bile salts in the jejunal remnant, everted sacs of jejunal remnants were prepared 3 months after ileectomy. The mean serosal to mucosal concentration ratio of taurocholate found in the experimental jejunal sacs was increased approximately 70 percent over the mean ratios of normal and sham-resected jejunal preparations (p smaller than 0.05). This change may be a manifestation of cellular adaptation in transport function, suggesting that the scope of intestinal adaptation in short gut syndrome goes beyond morphological hypertrophy and hyperplasia.