SHORT BOWEL SYNDROME
- After bowel resection, the remnant intestine displays evidence of epithelial cellular hyperplasia, villi lengthening,
- increase in intestinal absorptive surface area and and digestive and absorptive functions improve.
- Short bowel syndrome: presence of less than 200 cm of residual bowel in adult patients.
- Resection of less than 50% of the intestine is generally well tolerated.
- Resection of jejunum is better tolerated than resection of ileum, as the capacity for bile salt and vitamin B12 absorption is specific to the ileum
- Malabsorption after massive bowel resection is exacerbated by a characteristic hypergastrinemiaassociated gastric acid hypersecretion that persists for 1 to 2 years postoperatively
Risk factors for development of short bowel syndrome after massive bowel resection
- bowel length >200 cm
- Absence of ileocecal valve
- Absence of colon
- Diseased remaining bowel (e.g., Crohn’s disease)
- Ileal resection
Vitamin Deficiencies in Short Bowel Syndrome
- This is associated primarily with deficiency of fat soluble vitamins (A, D, E. K)
- The most common fat-soluble vitamins that are deficienci are vitamin A and D and to a lesser extent vitamin E followed by vitamin K.
- Vitamin A, D > Vitamin E >> Vitamin K
- Deficiency of vitamin K is uncommon as vitamin K is synthesized by colonic bacteria
- 60% of vitamin K is synthesized by colonic bacteria
- 40% of vitamin K is received by dietary intake
- Deficiency of vitamin K is therefore uncommon in patients with short bowel syndrome who have an intact colon.
- Deficiency of vitamin K is however common in those patients with short bowel syndrome who do not have a residual colon.
Short Bowel Syndrome with Extensive ileal resection
- This is associated primarily with deficiency of vitamin
- B12 since vitamin B12 is only absorbed in the terminal ileum.
- Fat soluble vitamin deficiencies may also occur due to fat malabsorption from decrease in concentration of bile acids / salts.
- (Bile acids are absorbed only from tr..; ileum)
Vitamin B12 > Fat solubleVitamin
- The ileum has the capacity to adapt and compensate for jejunal resection. The jejunum does not have the capacity to adapt and compensate for ileal resection (as the terminal ileum has the exclusive capacity to reabsorb bile salts &vit BO
- Cyanocobalamine (Vitamin B12) deficiency is the most common deficiency in patients with short bowel syndrome associated with loss of ileum (Heal resection) since vitamin B12 is absorbed only in the ileum
- Short Bowel Syndrome may be associated with deficiency offal-soluble vitamins (Vitamin A, D, E and K) and water soluble Vitamin B12 (when ileum is resected / non functional).
- The most common deficiency is determined essentially by the specific segment of the intestine (jejunum or ileum) that is resected / non functional
- Short bowel syndrome is characterized by increased gastrin levels (hypergastrinemia) due to reduced intestinal catabolism of gastrin
- Short bowel syndrome is a condition in which extensive resection of the bowel results in malabsorption, fluid and electrolyte loss and malnutrition. Short bowel syndrome can occur at any age from neonates through the elderly. Patients present with diarrhea, steatorrhea, increase in renal calcium oxalate calculi and cholesterol gallstones.
- Etiology: In neonates can result from jejunoileal atresia, gastrochisis, omphalocele and necrotizing enterocolitis (bowel is resected). In adults it occur after bowel resection secondary to trauma, chrons disease and mesenteric vascular disease. Following resection of the intestine, the residual intestine undergoes adaptation of both structure and function that may last for up to 6–12 months.