Bowel Obstruction (Small and Large)
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- Obstruction of normal intestinal flow from mechanical or nonmechanical causes
- Small-bowel obstruction (SBO):
- 20% of acute surgical admissions
- Adhesions: Most common cause (60%)
- Strictures: Inflammatory bowel disease
- Trauma: Bowel wall hematoma
- Miscellaneous (e.g., ascaris infection)
- Large-bowel obstruction (LBO):
- Disease primarily of the elderly
- Carcinoma (60%)
- Diverticular disease (20%)
- Volvulus (5%)
- Colitis (e.g., ischemic, radiation)
- Crohn's disease
- Foreign bodies
- Functional, nonmechanical:
- Paralytic ileus (e.g., electrolyte abnormalities, injury)
- Pseudo-obstruction (i.e., Ogilvie syndrome [e.g., operative and nonoperative trauma] 11%)
- Obstruction leads to proximal dilatation of intestines due to swallowed air and accumulated GI secretions, leading to increased intraluminal pressures.
- Retrograde peristalsis causes vomiting.
- Distended bowel becomes progressively edematous, and additional intestinal secretions cause further distention and 3rd spacing of fluid into the intestinal lumen.
- Obstruction may lead to intestinal wall ischemia (strangulated obstruction), resulting in increased aerobic and anaerobic bacteria, and methane and hydrogen production. Peritonitis, sepsis, and death may follow.
- Mortality is 100% in untreated strangulated obstruction, 8% if treated surgically within 36 hr, but 25% if surgery delayed after 36 hr.