Small Bowel Obstruction

Pt with h/o abdominal hernia, irritable bowel disease, intra-abdominal malignancy, and abdominal surgery presents with acute onset, generalized abdominal pain. Reports N/V. No flatus, bowel movement since abdominal pain began. Fever, abdominal distention, hypoactive high-pitched bowel sounds, tympany with abdominal percussion on exam.

  • CBC shows leukocytosis

  • CMP shows hypokalemic, hypochloremic metabolic alkalosis

  • Obtain serum lactate

  • Abdominal CT with IV contrast shows dilated small bowel loops proximal to obstruction with air-fluid levels >2.5 cm long and located at different heights within the same bowel loop (step-ladder distribution)

    • Uncomplicated bowel obstruction: Initiate bowel rest, abdominal exams q8 hours

    • Complicated bowel obstruction with evidence of vascular compromise, perforation, and/or closed loop obstruction: Obtain immediate surgical consult

  • Start normal saline at 125 cc/hr

  • Replete electrolytes

  • Fever and leukocytosis: Start metronidazole 500 mg IV q8 hours, ciprofloxacin 400 mg IV BID

  • Significant N/V and/or abdominal distention: Initiate decompression with NG tube

  • Presence of intra-abdominal malignancy: Consult hematology/oncology

  • Diet: NPO

Notes

  • Greatest risk factor is mechanical occlusion

    • Up to 75% of cases are due to surgical adhesions

    • Hernia, luminal masses due to IBD, and malignant may serve as nidus for obstruction

  • Strangulated hernia can lead to vascular compromise

  • Closed loop obstruction etiologies include intestinal volvulus