To investigate recovery of the allografted small intestine function after clinical small bowel transplantation (SBT).The structure of the graft was evaluated by endoscopic biopsy and histopathologic examination. Graft functions were assessed by D-xylose absorption, barium studies, nitrogen balance calculation, and blood and stool cultures. Nutritional status of the recipients was judged by measurement of body weight and serum protein concentrations.The recipient discontinued total parenteral nutrition (TPN) and resumed oral nutrition 100 d after SBT. On oral diet, the patient maintained a normal nutritional status, gained weight by 3 kg, and had a normal serum albumin concentration (40.2 g/L ± 0.2 g/L). Satisfactory D-xylose absorption was achieved 8 wk after the operation. Nitrogen balance of the gut was maintained well and increased gradually. Serial mucosal biopsy showed normal structures 2 wk after grafting, without evidence of rejection and graft versus host diseases (GVHD). Barium studies conducted on the 10(th) day and 38(th) day by barium studies revealed that the grafted small bowel motility showed normal patterns of peristalsis and transit. No bacterial translocations were noted.Function of the grafted small intestine recovered satisfactorily 100 d after transplantation, indicating good clinical outcome of SBT.