# Clinical Cases: Small Bowel 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
![Small Bowel Obstruction CT](case_01_image.jpg)

**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

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## Case 2: Small Bowel Crohn's Disease Requiring Surgery

### Patient Demographics
- **Age:** 34 years
- **Sex:** Male
- **Occupation:** Graphic designer

### Chief Complaint
"I've been having severe abdominal pain and can't eat without pain for weeks."

### History of Present Illness
The patient has a 10-year history of Crohn's disease, primarily involving the terminal ileum. He has been on various medications over the years. His disease has been increasingly difficult to control, with frequent flares. Over the past 2 months, he has developed persistent right lower quadrant pain, worse after eating. He has lost 8 kg despite trying to maintain nutrition. He has had near-obstructive symptoms with nausea and intermittent vomiting. His current medications have failed to control his symptoms.

### Past Medical History
- Crohn's disease (10 years)
  - Multiple flares requiring hospitalization
  - Currently on adalimumab (started 2 years ago)
  - Prior treatment with infliximab (lost response)
  - Perianal disease (history of abscess, now healed)
- No prior abdominal surgery
- Depression

### Medications
- Adalimumab 40 mg every 2 weeks (subtherapeutic drug levels)
- Prednisone 20 mg daily (for current flare)
- Budesonide 9 mg daily
- Azathioprine 150 mg daily
- Multivitamins, iron, vitamin B12

### Laboratory Results
- Hemoglobin: 10.2 g/dL
- Albumin: 2.8 g/dL
- CRP: 48 mg/L (elevated)
- Fecal calprotectin: >1000 μg/g (markedly elevated)
- Vitamin B12: Low
- Iron studies: Iron deficiency

### Imaging

**MR Enterography:**
- Marked wall thickening of terminal ileum (15 cm segment)
- Luminal narrowing with pre-stenotic dilation
- Stricture with upstream dilation
- Mucosal enhancement and edema
- Small mesenteric phlegmon
- No drainable abscess

**CT Abdomen/Pelvis:**
- Confirms MRI findings
- Near-complete obstruction at terminal ileum
- No perforation or abscess

**Colonoscopy (limited):**
- Unable to intubate terminal ileum due to stricture
- Mild colonic involvement
- Biopsies: Chronic active inflammation consistent with Crohn's

### Multidisciplinary IBD Conference
- Failed multiple biologics with progressive stricturing disease
- Near-obstructing stricture unlikely to respond to medical therapy
- Malnutrition requiring optimization
- Surgical consultation recommended

### Preoperative Optimization
1. **Nutritional support:** TPN initiated for 2 weeks
2. **Steroid management:** Stress-dose steroids perioperatively, then taper
3. **Hold biologics:** Adalimumab held 4 weeks before surgery
4. **Anemia:** Iron infusion, hemoglobin improved to 11.5 g/dL
5. **DVT prophylaxis:** Given IBD is a hypercoagulable state
6. **Smoking:** Patient is a non-smoker (good prognostic factor)

### Operative Procedure
Laparoscopic ileocolic resection:
- Identified diseased terminal ileum (20 cm strictured segment)
- Preserved maximum bowel length
- Resected diseased terminal ileum with small cecal cuff
- Stapled side-to-side, functional end-to-end ileocolic anastomosis
- No evidence of other skip lesions

### Pathology
- Terminal ileum: Transmural inflammation, fibrosis, stricture
- Consistent with Crohn's disease
- Margins: Microscopic inflammation present (common in Crohn's)
- No dysplasia or malignancy

### Postoperative Course
- Diet advanced POD 3
- Discharged POD 5
- Steroids tapered over 8 weeks
- GI follow-up for postoperative medical therapy

### Postoperative Medical Management
- Given high-risk features (young age, prior biologic failure, perianal disease):
  - Started ustekinumab 6 weeks postoperatively
  - Goal: Prevent/delay endoscopic recurrence

### Surveillance
- Colonoscopy at 6 months post-surgery (Rutgeerts score)
- Fecal calprotectin monitoring

### Teaching Points
1. Surgery is not "failure" in Crohn's - it's part of disease management
2. Indications: Stricture, perforation, abscess, medically refractory disease
3. Bowel-sparing surgery (limited resection) is the goal
4. Strictureplasty an option for non-phlegmonous strictures
5. Postoperative biologic therapy reduces recurrence
6. Smoking is the strongest modifiable risk factor for recurrence

### Clinical Image
![Crohn's Disease MR Enterography](case_02_image.jpg)

**Image Description:** MR enterography demonstrating terminal ileal wall thickening with luminal narrowing and upstream dilation characteristic of stricturing Crohn's disease. The "comb sign" of engorged vasa recta indicates active inflammation.

**Attribution:** Image from Wikimedia Commons. Source: https://commons.wikimedia.org/wiki/Category:Crohn%27s_disease

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## Case 3: Acute Mesenteric Ischemia

### Patient Demographics
- **Age:** 72 years
- **Sex:** Female
- **Occupation:** Retired teacher

### Chief Complaint
"I have terrible abdominal pain that doesn't match what the doctors are finding on exam."

### History of Present Illness
The patient presents with a 6-hour history of acute onset, severe, diffuse abdominal pain. She describes the pain as constant and "the worst she's ever felt." She had one episode of bloody diarrhea. She notes the pain seems out of proportion to what the doctors are finding when they examine her abdomen. She has a history of atrial fibrillation and admits to being non-compliant with her anticoagulation.

### Past Medical History
- Atrial fibrillation (not on anticoagulation - stopped due to "bleeding concerns")
- Hypertension
- Peripheral vascular disease
- Coronary artery disease (prior MI)
- Congestive heart failure (EF 40%)

### Medications
- Aspirin 81 mg daily (stopped warfarin 6 months ago)
- Metoprolol 50 mg BID
- Lisinopril 20 mg daily
- Furosemide 40 mg daily

### Physical Examination
- **Vitals:** BP 98/60 mmHg, HR 112 bpm (irregularly irregular), RR 24/min, Temp 37.8°C
- **General:** Elderly female in severe distress, restless
- **Cardiovascular:** Irregular rhythm, no murmurs
- **Abdomen:**
  - Initially: Soft, mild diffuse tenderness, NO peritoneal signs
  - **"Pain out of proportion to physical exam"** - classic finding
  - Bowel sounds: Initially present but hypoactive
  - No distension
- **Extremities:** Evidence of peripheral vascular disease

### Laboratory Results
- WBC: 18,400/μL (left shift)
- Hemoglobin: 14.8 g/dL (hemoconcentrated)
- Lactate: 5.8 mmol/L (markedly elevated)
- pH: 7.28 (metabolic acidosis)
- Base deficit: -8
- D-dimer: Elevated
- Creatinine: 1.6 mg/dL

### Imaging

**CT Angiography (CTA) Abdomen:**
- Filling defect in the superior mesenteric artery (SMA) - embolic occlusion
- Diminished enhancement of jejunal and ileal segments
- Bowel wall thickening
- Pneumatosis intestinalis in several loops (ominous sign)
- No portal venous gas

### Diagnosis
Acute mesenteric ischemia - SMA embolism

### Immediate Management
1. Aggressive fluid resuscitation
2. Broad-spectrum antibiotics
3. Correct acidosis
4. Anticoagulation with heparin
5. Emergent surgical exploration

### Operative Procedure
Emergency exploratory laparotomy:
- Findings: Ischemic jejunum and proximal ileum (200 cm involved)
- SMA explored - embolectomy performed via arteriotomy
- Excellent pulsatile flow restored after embolectomy
- Bowel reassessed after warm packs and time:
  - 80 cm of frankly necrotic bowel
  - Remaining bowel with questionable viability
- Resection of necrotic bowel
- Bowel left in discontinuity (damage control)
- Temporary abdominal closure
- Planned second-look laparotomy in 24-48 hours

### Second-Look Laparotomy (48 hours)
- Remaining bowel viable with good color and peristalsis
- Primary anastomosis performed (hand-sewn)
- 120 cm of small bowel remaining
- Abdomen closed

### Postoperative Course
- ICU care for 5 days
- Prolonged ileus
- Transitioned to TPN
- Eventually tolerating enteral nutrition
- Anticoagulation with warfarin initiated (goal INR 2-3)
- Discharged to rehabilitation on POD 14

### Long-Term Management
- Lifelong anticoagulation for atrial fibrillation
- Nutritional monitoring (short bowel concerns)
- May need supplemental nutrition support

### Teaching Points
1. Classic triad: Severe pain, pain out of proportion to exam, risk factor for embolism
2. Atrial fibrillation without anticoagulation is major risk factor
3. Lactate elevation indicates bowel ischemia
4. CTA is imaging modality of choice
5. Prompt revascularization is critical
6. Second-look laparotomy appropriate for questionable bowel viability
7. Delay in diagnosis dramatically increases mortality (>70% if bowel necrosis)

### Clinical Image
![Mesenteric Ischemia CT](case_03_image.jpg)

**Image Description:** CT angiography demonstrating filling defect in the superior mesenteric artery consistent with embolic occlusion. Associated findings include bowel wall thickening and decreased mucosal enhancement of the affected small bowel segments.

**Attribution:** Image from Wikimedia Commons. Source: https://commons.wikimedia.org/wiki/Category:Computed_tomography_angiography