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■ Intestinal perforation and bleeding
■ Pyelonephritis and nephrolithiasis
■ Malignant neoplasms

Small Bowel Obstruction (SBO)
SBO is a mechanical or functional obstruction of the small intestines. The nor-
mal transit of the products of digestion through the intestines is blocked.
Causes
■ Adhesions, hernias, volvulus, intussusception, strictures, abscess,
paralytic ileus
■ Crohn’s disease
■ Benign or malignant tumors
■ Foreign bodies
Pathophysiology
■ Intestinal contents, gas, and fluid accumulate above the obstruction →
abdominal distention and fluid retention →↓ venous and arteriolar capil-
lary pressure → edema, congestion of the intestine → rupture or perfora-
tion of the intestinal wall → peritonitis. ↓ blood supply to obstruction
→ ischemia → necrosis and gangrene of the intestine. Obstruction may
be partial or complete and may also lead to intestinal strangulation.
+ +
■ Reflex vomiting also occurs →↓ H and K → metabolic acidosis, and ↓ H 2 O
+
and ↓ Na → dehydration → hypovolemic shock.
■ Obstruction may resolve spontaneously.
Clinical Presentation
■ Crampy, colicky, wave-like central or midabdominal pain
■ No bowel movement and absence of flatus → abdominal distention →
bowel ischemia or perforation
■ Nausea and vomiting → dehydration (drowsiness, malaise, parched
tongue and mucous membranes, intense thirst) and electrolyte
imbalances → hypovolemic shock
■ Possible aspiration of vomitus (vomitus may be fecal in nature)

GI