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
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
