Abstract: | Each year, thousands of peoples die, suffering from an anatomical or functional loss of their intestine; these patients would benefit from bowel transplantation; the difficulties of bowel transplantation are as follows: 1. the physiological characteristics of the small bowel, and the fact that denervation, lymphatics interruption and ischemia, independently from rejection, may disturb its function; 2. secondly, the organ is septic; thus, its transplantation causes major infectious problems; 3. at last, the immunological characteristics of the intestinal allograft. Bowel transplantation causes a two-way immunological conflict, not only a standard rejection response, but also a graft-versus-host disease, similar to that observed after bone marrow transplantation; this reaction is caused by the lymphoid tissue conveyed within the bowel graft. The introduction of a new immunosuppressive molecule, FK 506, in combination with profound antibiotic prophylactic regimens, decontamination protocols and vigorous anti-viral protection (against cytomegalovirus and Epstein-Barr), have significantly improved the results. Bowel transplantation has recently reached clinical application. The one-year survival rate of intestinal grafts reaches now 70%. Still, there is no doubt that, due to its microbiological and immunological characteristics, the small bowel will remain the most challenging abdominal organ to transplant. |