ABSTRACT
Intestinal failure (IF) or short bowel syndrome (SBS) is de—ned as a malabsorptive state that results from insuf—cient intestinal surface area, resulting in inadequate nutritional and «uid absorption leading to long-term total parenteral nutrition (PN). As discussed in Chapter 1 (Etiology and Epidemiology of Intestinal Failure), in adults, this most commonly occurs from surgical resection of a large portion of the small bowel and/or the colon. SBS in children or infants may be postsurgical from congenital malformations, necrotizing enterocolitis, in«ammatory bowel disease, or vascular thromboses. In adults, this syndrome often occurs when <200 cm of the intestine remains in an affected individual. However, there is signi—cant variation as the syndrome largely depends on the extent of resection, location of resection(s), and eventual compensatory intestinal adaptation of the remaining intact bowel. Examples range from patients with limited ileocolonic resection, where mild-to-moderate nutritional decline can be seen, to those with severe malabsorption such as in individuals with extensive ileal and colonic resection who may have a duodenostomy, proximal jejunostomy, or a jejunocolonic anastomosis.1−3
2.1 Intestinal Failure ..................................................................................................................... 13 2.2 Histology ................................................................................................................................. 14 2.3 GI Motility .............................................................................................................................. 14 2.4 Oropharynx and Esophagus .................................................................................................... 14 2.5 Stomach ................................................................................................................................... 15 2.6 Duodenum ............................................................................................................................... 17 2.7 Jejunum ................................................................................................................................... 18 2.8 Ileum ....................................................................................................................................... 18 2.9 Large Intestine ........................................................................................................................ 18 2.10 Digestion and Absorption ....................................................................................................... 19 2.11 Carbohydrates ......................................................................................................................... 19 2.12 Protein ..................................................................................................................................... 19 2.13 Lipids .......................................................................................................................................20 2.14 Water, Electrolytes, Minerals, Vitamins, and Trace Elements ...............................................20 2.15 Pathophysiology ......................................................................................................................22 2.16 Intestinal Adaptation ...............................................................................................................23 2.17 Jejunal Resection and Extensive Bowel Resection .................................................................24 2.18 Ileal Resection .........................................................................................................................26 2.19 Colonic Resection ...................................................................................................................28 2.20 Conclusion ...............................................................................................................................28 References ........................................................................................................................................28
