General Surgery · Year 3 · from General Surgery

Case 1: Adhesive Small Bowel Obstruction

Patient Demographics

  • Age: 62 years
  • Sex: Female
  • Occupation: Retired administrative assistant

Chief Complaint

"I haven't been able to keep anything down and my belly is bloated."

History of Present Illness

The patient presents with a 2-day history of progressively worsening abdominal distension, nausea, and vomiting. The vomiting has become bilious and more frequent. She reports crampy, diffuse abdominal pain that comes in waves. She has not passed flatus or had a bowel movement in 36 hours. She had a similar episode 2 years ago that resolved with nasogastric decompression. She has a history of open appendectomy 30 years ago and total abdominal hysterectomy 15 years ago.

Past Medical History

  • Hypertension
  • Type 2 diabetes
  • Hyperlipidemia
  • Previous surgeries:
  • Open appendectomy (30 years ago)
  • Total abdominal hysterectomy (15 years ago)
  • Prior SBO (2 years ago, non-operative management)

Medications

  • Metformin 1000 mg BID
  • Lisinopril 20 mg daily
  • Atorvastatin 40 mg daily

Physical Examination

  • Vitals: BP 138/82 mmHg, HR 98 bpm, RR 20/min, Temp 37.2°C
  • General: Uncomfortable female, appearing moderately distressed
  • Abdomen:
  • Distended, tympanitic
  • Diffuse tenderness without peritoneal signs
  • Multiple well-healed surgical scars (McBurney's, midline vertical)
  • High-pitched bowel sounds with rushes
  • No hernias

Laboratory Results

  • WBC: 11,200/μL
  • Hemoglobin: 13.8 g/dL
  • Creatinine: 1.4 mg/dL (baseline 0.9)
  • BUN: 32 mg/dL
  • Potassium: 3.2 mEq/L
  • Chloride: 94 mEq/L
  • Lactate: 1.6 mmol/L

Imaging

Abdominal X-ray:

  • Multiple dilated loops of small bowel
  • Air-fluid levels
  • Paucity of gas in the colon
  • No free air

CT Abdomen/Pelvis with IV contrast:

  • Small bowel obstruction with transition point in the mid-abdomen
  • Dilated proximal small bowel (up to 4.5 cm)
  • Decompressed distal small bowel and colon
  • Transition point at an adhesive band near a prior surgical site
  • No evidence of closed loop obstruction
  • Bowel wall enhancement intact (no ischemia)
  • Small bowel feces sign present

Diagnosis

Adhesive small bowel obstruction without signs of strangulation

Initial Management (Non-operative Trial)

  1. NPO status
  2. Nasogastric tube decompression
  3. IV fluid resuscitation (correct dehydration)
  4. Electrolyte replacement
  5. Foley catheter (monitor urine output)
  6. Serial abdominal examinations every 4-6 hours
  7. Hold metformin

Monitoring Parameters

  • Abdominal examination for signs of peritonitis
  • NGT output (initially 800 mL/8 hours)
  • Urine output goal >0.5 mL/kg/hr
  • Lactate trending

Clinical Course - Day 2

  • Some improvement in distension
  • NGT output decreasing
  • No flatus yet
  • Repeat KUB: Slight improvement

Gastrografin Challenge

  • Water-soluble contrast (gastrografin) given via NGT
  • 8-hour follow-up X-ray: Contrast in right colon
  • Indicates passage through obstruction
  • Favorable for resolution with continued conservative management

Clinical Course - Day 3

  • Passed flatus
  • NGT output minimal
  • Abdomen softer, less distended
  • NGT clamped, then removed

Diet Advancement

  • Clear liquids started
  • Advanced to low-residue diet over 48 hours
  • Tolerated regular diet by Day 5

Discharge

  • Discharged Day 6
  • Diet counseling (small, frequent meals, chew thoroughly)
  • Return precautions for recurrent obstruction
  • Discussed surgical options for recurrent episodes

Long-term Considerations

  • Recurrent SBO risk: 30% with history of prior episode
  • Elective adhesiolysis controversial (creates new adhesions)
  • Surgery reserved for:
  • Failure of non-operative management
  • Signs of strangulation
  • Frequent recurrences affecting quality of life

Teaching Points

  1. Most SBOs are caused by adhesions from prior surgery
  2. CT with IV contrast is imaging modality of choice
  3. Signs of strangulation mandate urgent surgery
  4. Non-operative trial appropriate without strangulation
  5. Gastrografin challenge both diagnostic and therapeutic
  6. Surgery indicated for failure of conservative management or clinical deterioration

Clinical Image

Image Description: CT scan demonstrating small bowel obstruction with dilated, fluid-filled loops of proximal small bowel and a clear transition point to decompressed distal bowel. The "small bowel feces sign" indicates prolonged intestinal stasis.

Attribution: Image from Wikimedia Commons, Category:US medical imaging public domain images. Source: https://commons.wikimedia.org/wiki/Category:US_medical_imaging_public_domain_images

All cases for this lecture as Markdown