From the Guidelines
The workup for ischemic colitis should prioritize a comprehensive approach, starting with a thorough clinical assessment, and include imaging with CT scan and colonoscopy, as well as management with bowel rest, IV fluids, and antibiotics, with early surgical consultation for patients with peritoneal signs or clinical deterioration, as recommended by recent guidelines 1.
Initial Evaluation
The initial evaluation should include a complete history focusing on risk factors (vascular disease, recent hypotension, medications), physical examination, and laboratory tests including complete blood count, comprehensive metabolic panel, lactate level, and inflammatory markers like C-reactive protein. Stool studies should be obtained to rule out infectious causes.
Imaging
Imaging begins with abdominal X-rays to assess for obstruction or perforation, followed by CT scan with IV contrast which may show bowel wall thickening, "thumbprinting," or pneumatosis.
- CT findings that should prompt immediate surgical intervention include lack of bowel wall enhancement, free intraperitoneal air, pneumatosis intestinalis, and portal venous gas 1.
Diagnostic Testing
Colonoscopy is the gold standard diagnostic test, typically performed within 48 hours of presentation, revealing segmental erythema, edema, ulcerations, or bluish discoloration, most commonly affecting the watershed areas like the splenic flexure and sigmoid colon. Biopsies should be taken during colonoscopy to confirm diagnosis and rule out other conditions.
Management
Management includes bowel rest, IV fluids, antibiotics (typically a combination like piperacillin-tazobactam or ceftriaxone plus metronidazole), and close monitoring for complications such as perforation, stricture formation, or fulminant colitis requiring surgical intervention.
- Broad-spectrum antibiotics should be administered immediately, and patients should be anticoagulated with intravenous unfractionated heparin, unless contraindicated 1.
Surgical Intervention
Early surgical consultation is recommended for patients with peritoneal signs, significant bleeding, or clinical deterioration. Prompt laparotomy should be done for patients with overt peritonitis 1.
- Endovascular revascularization procedures may have a role with partial arterial occlusion, but solely endovascular options are limited in patients with bowel infarction and peritonitis 1.
From the Research
Diagnostic Approach
- The diagnosis of ischemic colitis typically involves a combination of clinical presentation, laboratory tests, imaging studies, and endoscopy 2, 3, 4, 5, 6.
- Computed tomography (CT) scan of the abdomen and pelvis with oral and IV contrast is the imaging modality of choice to support clinical diagnosis, define the severity and distribution of ischemia, and has prognostic value 2, 3.
- Lower gastrointestinal endoscopy, such as colonoscopy, should be performed within 48 hours to reach the distal-most extent of the disease and provide endoscopic and histological confirmation 2, 5, 6.
Medical Management
- The mainstay of medical management is conservative/supportive treatment, including bowel rest, fluid resuscitation, and antibiotics 2, 3, 5, 6.
- Broad-spectrum antibiotics should be initiated, and surgical consultation should be obtained in cases of severe disease, pancolonic ischemia, and isolated right colonic ischemia 3.
- Supportive care with intravenous fluids, optimization of hemodynamic status, avoidance of vasoconstrictive drugs, and empiric antibiotics will produce clinical improvement within 1 to 2 days in most patients 5.
Surgical Intervention
- Surgery should be performed for peritonitis, hemodynamic instability, or failure of non-operative management 3, 4, 6.
- Surgical resection of the affected segment should be considered early to minimize adverse outcomes, such as bowel perforation, peritonitis, persistent bleeding, protein-losing colopathy, and symptomatic intestinal strictures 4, 6.
- Specific laboratory, radiological, and endoscopic features are recognized to correlate with more severe disease, higher rates of surgical intervention, and ultimately worse outcomes, and should be carefully considered when deciding on the need for and timing of surgical intervention 2.