What are the colonoscopy findings and management options for ischemic colitis?

Colonoscopy Findings and Management of Ischemic Colitis

Colonoscopy is the diagnostic procedure of choice for ischemic colitis, with characteristic findings including normal rectum, sharply defined segmental involvement (particularly in the "watershed territory" from sigmoid colon to splenic flexure), petechial hemorrhages, and longitudinal ulcerations. 1

Endoscopic Findings in Ischemic Colitis

Characteristic Colonoscopic Findings

• Location pattern:

  • Predominantly left-sided colonic involvement (sigmoid, descending colon, splenic flexure)
  • Segmental distribution with sharp demarcation between affected and normal mucosa
  • Rectal sparing (normal rectum) is a key distinguishing feature 1, 2

• Mucosal appearance:

  • Edematous and fragile mucosa
  • Petechial hemorrhages
  • Segmental erythema
  • Scattered erosions
  • Longitudinal ulcerations 2
  • Cyanotic appearance in severe cases

Distribution of Lesions

• Segmental involvement is typical:
  • Descending colon: 16% of cases
  • Splenic flexure: 14% of cases
  • Sigmoid colon: 23% of cases 2
  • "Watershed territory" (sigmoid to splenic flexure) is most commonly affected 1

Evolution of Findings

• Rapid resolution on serial examinations is characteristic of ischemic colitis 1
• In chronic cases, stricture formation may develop with luminal narrowing 2

Diagnostic Approach

Endoscopic Evaluation

• Flexible sigmoidoscopy is often sufficient for diagnosis in the acute setting 1
• Full colonoscopy may be risky during acute presentation and should be avoided 1
• Biopsy from at least one site is essential for diagnosis and excluding other causes 1

Supportive Diagnostic Tests

• CT scan of abdomen and pelvis can show:
  • Mesenteric vessel engorgement
  • Bowel wall thickening
  • Fluid-filled colonic distention 1
  • However, CT has limited specificity (75-78%) 1

Histopathologic Features

• Mucosal inflammation with erosions
• Lamina propria hemorrhage
• Macrophages with hemosiderin pigmentation in submucosa
• Granulation tissue hyperplasia and gland atrophy 2

Classification and Management

Types of Ischemic Colitis

1. Non-gangrenous type (most common):

   • Reversible ischemic colitis (transient)
   • Chronic ischemic colitis (may lead to strictures)

2. Gangrenous type (rare but severe):

   • Characterized by cyanotic mucosa and pseudopolyps
   • Requires urgent surgical intervention 2, 3

Management Approach

• Mild cases (non-gangrenous):

  • Conservative management
  • Bowel rest
  • Intravenous fluids
  • Antibiotic therapy if indicated
  • Serial physical examinations 4

• Severe cases or clinical deterioration:

  • Prompt surgical consultation
  • Resection of affected segment if:
    • Peritoneal signs develop
    • Persistent bleeding occurs
    • Clinical deterioration despite medical management 5, 6

Follow-up

• Serial colonoscopies to monitor healing
• Most transient cases resolve without complications
• Watch for development of strictures in chronic cases 3, 4

Clinical Pearls and Pitfalls

Risk Factors to Consider

• Elderly patients (majority over 50 years)
• Hypertension, cardiovascular disorders, diabetes
• History of abdominal surgery 2

Differential Diagnosis

• Inflammatory bowel disease
• Infectious colitis
• Radiation colitis
• Immune checkpoint inhibitor colitis 1

Complications to Monitor

• Bowel perforation
• Peritonitis
• Persistent bleeding
• Protein-losing colopathy
• Symptomatic intestinal strictures 5

Colonoscopy with biopsy remains the gold standard for diagnosis of ischemic colitis, with a diagnostic accuracy of over 90%. The typical endoscopic findings, when combined with clinical presentation and histopathology, allow for prompt diagnosis and appropriate management, significantly reducing morbidity and mortality.