What are the signs and symptoms of intestinal ischemia or perforation?

Signs and Symptoms of Intestinal Ischemia or Perforation

The most common signs and symptoms of intestinal ischemia or perforation include abdominal pain (74-95%), guarding/rebound tenderness (82.5%), tachycardia (62.5%), leukocytosis (40%), fever (38%), rectal bleeding (15%), and abdominal distension (6.6%). 1

Clinical Presentation of Intestinal Ischemia

Common Symptoms

• Colicky abdominal pain that may become severe and unresponsive to analgesics when ischemia progresses 2, 3
• Nausea and vomiting, especially in small bowel ischemia 2, 4
• Bloody diarrhea or hematochezia 4, 5
• Abdominal distension 2
• Absence of passage of flatus (90% of cases) 2
• Absence of bowel movements (80.6% of cases) 2

Physical Examination Findings

• Abdominal tenderness, often localized to the left side in colonic ischemia 4, 3
• Abdominal distension with a positive likelihood ratio of 16.8 1
• Hyperactive or absent bowel sounds 2
• Signs of peritoneal irritation in advanced cases 1

Laboratory Findings

• Leukocytosis with neutrophilia 2, 4
• Elevated lactic acid levels (indicating tissue hypoperfusion) 2, 6
• Low serum bicarbonate levels and arterial blood pH 2
• Elevated amylase levels 2
• Abnormal renal function tests indicating dehydration 2

Clinical Presentation of Intestinal Perforation

Common Symptoms

• Sudden onset of severe abdominal pain 1
• Abdominal distension 1
• Nausea and vomiting 1
• Rectal bleeding (in some cases) 1

Physical Examination Findings

• Diffuse peritonitis with guarding and rebound tenderness 1
• Abdominal distension 1
• Tachycardia (62.5%) 1
• Fever (38%) 1
• Absent bowel sounds 2
• Subcutaneous emphysema (rare) 1

Laboratory Findings

• Leukocytosis (40%) 1
• Elevated C-reactive protein (CRP) 1
• Elevated procalcitonin (PCT) in cases of delayed presentation (>12h) 1

Warning Signs of Complications

• Intense pain unresponsive to analgesics suggests strangulation/ischemia 2
• Fever, tachypnea, tachycardia, and confusion indicate systemic inflammatory response 2
• Diffuse abdominal tenderness, guarding, or rebound tenderness suggest peritonitis 1, 2
• Hypotension, cool extremities, mottled skin, and oliguria are signs of shock 1, 2
• Feculent vomiting can indicate distal large bowel obstruction 2

Diagnostic Approach

Initial Assessment

• Complete history focusing on previous abdominal surgeries, diverticulitis episodes, chronic constipation, rectal bleeding, or unexplained weight loss 2
• Examination of all hernia orifices and previous surgical incision sites 1, 2
• Digital rectal examination to detect blood or rectal mass 2

Laboratory Tests

• Complete blood count to assess for leukocytosis 1
• Electrolyte panel to identify imbalances 2
• Renal function tests to evaluate dehydration 2
• Lactate levels to assess for intestinal ischemia 2, 6
• C-reactive protein and procalcitonin for inflammatory markers 1

Imaging Studies

• CT scan is the most accurate diagnostic tool (>90% accuracy) for detecting perforation 1
• CT scan can detect small amounts of free intra-peritoneal air and fluid 1
• Multi-detector CT (MDCT) is 86% accurate in predicting the site of perforation 1
• Plain abdominal X-rays have limited diagnostic value (sensitivity 50-60%) but can detect free air 1, 2
• Colonoscopy is the gold standard for diagnosing ischemic colitis 4

Differences Between Small and Large Bowel Involvement

• Small bowel ischemia/perforation typically presents with earlier and more frequent vomiting 2
• Colonic ischemia often presents with left-sided abdominal pain and bloody diarrhea 4, 3
• Large bowel obstruction/perforation has a more gradual development of symptoms 2
• Patients with colonic ischemia are often older than those with mesenteric ischemia (77 vs. 61 years) 5
• Patients with colonic ischemia are more likely to present with GI bleeding (90% vs. 11%) but less likely to report abdominal pain as their primary complaint (10% vs. 89%) compared to mesenteric ischemia 5

Clinical Pitfalls and Caveats

• Colonic ischemia is often misdiagnosed in the emergency department (only 9% receive correct ED diagnosis) 5
• Peritonitis-like clinical scenarios can occur in the absence of perforation (e.g., transmural thermal injury after polypectomy) 1
• Elderly or unconscious patients may have minimal signs on clinical examination despite severe disease 1, 3
• A small number of patients with intestinal perforation (5%) may remain asymptomatic 1
• Delay in diagnosis beyond 24 hours increases the likelihood of requiring more invasive treatments 1