Short bowel syndrome occurs when there is insufficient small intestine length (less than 200cm in adults) or function to absorb nutrients, resulting in diarrhea, dehydration, and malnutrition. The most common causes are mesenteric ischemia, Crohn's disease, and malignancy in adults, and volvulus, necrotizing enterocolitis, and atresias in children. Treatment involves managing the underlying condition, replacing fluids and electrolytes, total parenteral nutrition (TPN), and gradually introducing enteral nutrition with acid suppression and antimotility drugs. During adaptation, the remaining intestine undergoes changes to increase absorption over 1-2 years to reduce TPN dependence. With less than 60cm of small bowel in adults

1. Short bowel syndrome
Yonas Ademe
Jan, 2017

2. Introduction
• Short-bowel syndrome has been arbitrarily
defined as the presence of less than 200 cm of
residual small bowel in adult patients
• A functional definition, in which insufficient
intestinal absorptive capacity results in the
clinical manifestations of diarrhea, dehydration,
and malnutrition, is more broadly applicable

3. Etiologies
• In adults, the most common etiologies of short-
bowel syndrome are:
– Acute mesenteric ischemia
– Crohn's disease
– Malignancy
• 75% of cases result from resection of a large amount
of small bowel at a single operation
– Typical of patients with acute mesenteric ischemia
• 25% of cases result from the cumulative effects of
multiple operations during which small intestine is
resected
– Typical of patients with Crohn's disease

4. Cont.
• Most common etiologies in pediatric patients
– Volvulus
– Necrotizing enterocolitis
– Intestinal atresias

5. Pathophysiology
• Resection of less than 50% of the small intestine
is generally well tolerated
– However, clinically significant malabsorption occurs
when greater than 50 to 80% of the small intestine
has been resected

6. Cont.
• Residual bowel length is not the only factor
predictive of achieving independence from
TPN (enteral autonomy)
– There are several other determinants of the
severity of malabsorption
• Presence or absence of an intact colon
• Presence or absence of an intact ileocecal valve
• Part of small intestine resected
• A healthy or diseased residual small intestine

7. Cont.
• The colon has the capacity to absorb large
fluid and electrolyte loads
• In addition, the colon can play an important,
albeit small, role in nutrient assimilation by
absorbing short-chain fatty acids

8. Cont.
• A healthy, rather than diseased, residual small
intestine is associated with decreased severity
of malabsorption

9. Cont.
• An intact ileocecal valve is believed to be
associated with decreased malabsorption
– The ileocecal valve delays transit of chyme from the
small intestine into the colon, thereby prolonging
the contact time between nutrients and the small-
intestinal absorptive mucosa

10. • Resection of jejunum is better tolerated than
resection of ileum, because the capacity for
bile salt and vitamin B12 absorption is specific
to the ileum

11. Cont.
• TPN dependence
– Among adult patients who have an intact and
functional colon, lifelong TPN dependence is likely to
persist if there is less than 60 cm of residual small
intestine
– Among adult patients who lack a functional colon,
lifelong TPN dependence is likely to persist if there is
less than 100 cm of residual small intestine
– Among infants with short-bowel syndrome, weaning
from TPN-dependence has been achieved with as
little as 10 cm of residual small intestine

12. Cont.
• During the first 1 to 2 years following massive
small-bowel resection, the remaining intestine
undergoes compensatory adaptation
• Clinically, the period of adaptation is associated
with:
– Reductions in volume and frequency of bowel
movements
– Increases in the capacity for enteral nutrient
assimilation
– Reductions in TPN requirements

13. Treatment
• Medical therapy
– Management of the primary condition precipitating
the intestinal resection
– Depletion of fluid and electrolytes lost in the severe
diarrhea that characteristically occurs
– TPN (at least initially)
• Enteral nutrition (Gradually introduced)
– Anti-acids (High-dose H-2 receptor antagonists or
PPIs)
– Antimotility agents (Such as loperamide
hydrochloride)

14. Cont.
• During the period of adaptation TPN and enteral
nutrition are titrated in an attempt to allow for
independence from TPN
• Patients who remain dependent on TPN face
substantial TPN-associated morbidities, including:
– Catheter sepsis
– Venous thrombosis
– Liver
– Kidney failure
– Osteoporosis

15. Cont.
• Surgical therapy
– Nontransplant Surgical Therapy
• E.g Small bowel lengthening
– Intestinal transplantation

16. Prognosis
• Approximately 50 to 70% of patients with short-
bowel syndrome who initially require TPN are
ultimately able to achieve independence from
TPN
• Prognosis for achieving enteral autonomy is
better among pediatric patients than among
adults

17. End!