title: Physiology of the small intestine after resection and transplant.
abstract: OBJECTIVE
  Recent studies have evaluated intestinal physiology following bowel resection; understanding changes in small bowel physiology after intestinal transplantation has received less attention. In this review, we will examine recent studies focused on changes in intestinal physiology following resection and intestinal transplantation.
  
  
  RESULTS
  Absorption, immunity, and motility are fundamental components of small bowel physiology. Absorption after resection or transplantation is mediated by adaptation and enterocyte function. After resection, adaptation results in increased villus height and crypt depth. Hepatocyte growth factor and epidermal growth factors cause enterocyte hypertrophy and hyperplasia, allowing greater peptide uptake. Little is known about intestinal adaptation after transplant, but enteral autonomy is attainable. Immunity in small bowel after transplantation relies on a balance of innate and adaptive immune responses in the presence of the luminal microbiota. Intraepithelial lymphocytes are decreased following small bowel resection. After small bowel transplant, the number and the ratio of intraepithelial lymphocytes to enterocytes, as well as changes in the microbiota, can be used to identify rejection. After intestinal transplant, immune-mediated dysmotility is common. Perioperative infliximab in addition to tacrolimus may decrease the inflammation that contributes to dysmotility.
  
  
  CONCLUSIONS
  As intestinal transplantation becomes more successful, understanding how absorption, immunity, and motility changes will allow for optimization of bowel function.
authors: The Department of Pediatric Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, USA.
authors: Ashley
authors: A
authors: Walther
authors: Abigail
authors: A
authors: Coots
authors: Jaimie
authors: J
authors: Nathan
authors: Samuel
authors: S
authors: Kocoshis
authors: Greg
authors: G
authors: Tiao
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D056704:Adaptive Immunity; D005769:Gastrointestinal Motility / Q000502:physiology; D006801:Humans; D007113:Immunity, Innate; D007408:Intestinal Absorption / Q000502:physiology; D007421:Intestine, Small / Q000276:immunology / Q000503:physiopathology* / Q000601:surgery / Q000637:transplantation; D008286:Malabsorption Syndromes / Q000601:surgery*; D011184:Postoperative Period; D012778:Short Bowel Syndrome / Q000601:surgery