Bowel Obstruction
Tad Kim, M.D.
Connie Lee, M.D.

Bowel Obstruction
• Ileus = obstruction 2/2 dysfunctional motility of bowel
• Mechanical obstruction = 85% SB, 15% large bowel
• Simple obstruction
• Closed loop obstruction
• Strangulation

Bowel Obstruction
• Adhesion #1 (80-90% of SBO in pt’s w/prior abdominal surgery)
• Hernia #2 overall - #1 cause of SBO in pts w/o prior abdominal surgery
• Tumor
• Abscess
• Hematoma
• Annular pancreas
• SMA syndrome
• Congenital lesions
• Gallstone ileus
• Intussusception
• Foreign body (bezoars, worms, etc)
• Meconium ileus
• Malrotation

Bowel Obstruction
• Cancer #1 (60%)
• Volvulus (sigmoid > cecum)
• Adhesions
• Hernia
• UC
• Diverticulitis
• Congenital lesions
• Fecal impaction
• Adynamic ileus
• Hirschsprung’s
• Meconium ileus
• Foreign body

Bowel Obstruction
• Age matters!
– Neonate: meconium ileus, Hirschsprung’s, malrotation, atresia
– Child: intussusception, Hirschsprung’s
– Adult: hernia, IBD, CA, diverticular disease
– Elderly: CA, diverticular disease, Ogilvie’s

Bowel Obstruction
• Proximal obstruction: early bilious vomiting, +flatus/BM
• Distal obstruction: obstipation, distension, vomiting feculent material
(2/2 bacterial overgrowth of SB contents)
• Pain w/obstruction: begins as cramping pain, changes to continuous severe pain w/strangulation & peritonitis
• PMHx: remember to ask about cardiac history (arrhythmias, prior MI,
Afib - think about intestinal ischemia), IBD, gallstones, cancer
• PSHx: remember to ask about ostomy output
• Meds: narcotics (ileus), antipsychotics (ileus), diuretics (hypoK a/w ileus)
• ROS: recent weight loss (CA, SMA syndrome)

Bowel Obstruction
• Start with ABCs
• Look for surgical scars
• Bowel sounds
• Distention: distal obstruction >> proximal
• Localized tenderness: think peritonitis
• Look for hernias/masses
• Do a rectal exam

Bowel Obstruction
• WBC (nml in uncomplicated SBO)
• CBC (anemia w/CA)
• BMP (hypoK)
• Alkalosis (a/w proximal obstruction)
• Acidosis (a/w bowel infarction)
• Amylase (may be elevated in SBO)

Bowel Obstruction
• Upright CXR: look for free air
• Flat and upright/left lateral decubitus: look for dilated bowel loops, air-fluid levels
• Note: if cecal diameter >12cm, there is a risk of perforation. At 12-14cm, the wall tension > perfusion pressure, increasing risk of necrosis
• Barium enema
• UGI series w/SB follow-through
• CT scan

Bowel Obstruction
• NPO, NGT, Foley, IVF
• Electrolyte replacement
• Many partial obstructions will resolve
• “Don’t let the sun set on a (complete) SBO”
• Complete bowel obstruction w/concern for strangulation/perforation requires immediate operative intervention (resuscitate first)

Bowel Obstruction
A 72-year-old woman presented with a 2-day history of abdominal pain associated with nausea and vomiting
Dedouit F and Otal P. N Engl J Med 2008;358:1381

Bowel Obstruction
A 48-year-old healthy woman presented with anorexia of 2 days' duration and abdominal pain in the right lower quadrant
Liu K and Lin B. N Engl J Med 2007;356:1152

Bowel Obstruction
A 60-year-old woman presented to the outpatient clinic with vague abdominal discomfort that had developed over the previous several weeks
Jang M and Lee K. N Engl J Med 2008;358:e16

Bowel Obstruction
A 68-year-old man with alcoholic cirrhosis, portal hypertension, ascites, and an umbilical hernia presented to the emergency department after an episode of coughing that was followed by a rush of fluid and fat from the umbilicus
Miryala R and Neilan R. N Engl J Med 2009;360:e32

Bowel Obstruction
Ingested magnets
Avolio L and Martucciello G. N Engl J Med 2009;360:2770

Bowel Obstruction
A 68-year-old man with chronic dysuria and increased urinary frequency presented with three weeks of weakness and fever
Rosmarin D and Tan C. N Engl J Med 2006;355:601

Bowel Obstruction
Radiographic Findings in Body Packers
Traub S et al. N Engl J Med 2003;349:2519-2526

Bowel Obstruction
An 83-year-old woman was hospitalized with nausea, vomiting, and obstipation
Graham J and Rothwell B. N Engl J Med 2004;351:1119

Bowel Obstruction
A previously healthy 102-year-old woman was admitted with abdominal pain and a 3-day history of vomiting
Chan D. N Engl J Med 2006;355:1714

Bowel Obstruction
A 64-year-old woman with ulcerative colitis presented with abdominal pain
Kurer M and Chintapatla S. N Engl J Med 2007;356:1656

Bowel Obstruction
• Always start with ABC, resuscitation
– Includes 2 large bore IV, Foley, NGT, monitor
• DDX is simple:
– SBO: A dhesions, B ulges, C ancer, C rohn’s
– LBO: CANCER , Volvulus, Diverticulitis
• Labs to assess dehydration & leukocytosis
• Imaging to assess obstruction & etiology
• If hypoTN/shock, “toxic”, or signs of strangulation or ischemia, resusc & OR stat
• Otherwise, for SBO, NGT & treat etiology
• LBO is different: really must rule out cancer, colonoscopy plays a larger role than w SBO