What are the recommended steps for a patient with diffuse abdominal pain and dark red stools?

Management of Diffuse Abdominal Pain and Dark Red Stools

A patient presenting with diffuse abdominal pain and dark red stools requires immediate hemodynamic assessment and resuscitation, followed by urgent upper endoscopy within 24 hours to identify and treat the bleeding source, as this presentation suggests upper gastrointestinal bleeding with potential hemodynamic compromise. 1

Immediate Assessment and Stabilization

Hemodynamic Evaluation

• Assess vital signs immediately to determine shock status: pulse >100 beats/min and systolic BP <100 mmHg define hemodynamic instability 1
• Dark red stools (melena) with diffuse abdominal pain strongly suggest upper GI bleeding, which carries higher mortality risk than lower GI sources 1, 2
• Evaluate for signs of peritonitis (rebound tenderness, guarding) which would indicate possible perforation requiring emergency surgery 3

Resuscitation Protocol

• Begin aggressive IV fluid resuscitation with crystalloid immediately to normalize blood pressure and heart rate before endoscopic evaluation 1
• Transfuse packed red blood cells to maintain hemoglobin >7 g/dL; use a threshold of 9 g/dL if massive bleeding, cardiovascular disease, or significant comorbidities are present 3, 1
• Correct electrolyte abnormalities and coagulopathy 3
• Insert nasogastric tube to protect airway, decompress stomach, and assess for blood or coffee grounds 3

Diagnostic Approach

Risk Stratification

• Calculate Glasgow-Blatchford score immediately - a score of 0 has a likelihood ratio of 0.02 for requiring urgent intervention, effectively ruling out need for emergency endoscopy 2
• Melena on examination increases likelihood of upper GI bleeding (LR 25), while blood clots in stool make upper GI source unlikely (LR 0.05) 2
• Nasogastric lavage showing blood or coffee grounds has LR 9.6 for upper GI bleeding 2

Laboratory Testing

• Obtain complete blood count, basic metabolic panel, coagulation studies, liver function tests, and type/crossmatch 1, 4
• BUN:creatinine ratio >30 strongly suggests upper GI bleeding (LR 7.5) 2
• Blood cultures are not routinely needed for community-acquired presentations unless patient appears septic 3

Imaging Decisions

• CT scan is NOT necessary if patient has obvious peritonitis requiring immediate surgery 3
• For hemodynamically stable patients without peritonitis, CT angiography should be performed to evaluate for mesenteric ischemia, which presents with diffuse pain and can cause bloody stools 3
• CT has 93% sensitivity and 100% specificity for acute mesenteric ischemia and should be done despite renal failure concerns, as delayed diagnosis is more harmful 3

Urgent Endoscopic Management

Timing and Approach

• Perform esophagogastroduodenoscopy (EGD) within 24 hours for hemodynamically stable patients 1, 4
• Emergency endoscopy should occur immediately if patient remains unstable despite resuscitation or has evidence of ongoing massive bleeding 1
• EGD has both diagnostic and therapeutic capabilities and is the procedure of choice 1

Endoscopic Findings and Treatment

• Look for peptic ulcer disease, gastric erosions, esophagitis, Mallory-Weiss tears, and vascular malformations 1
• Apply endoscopic hemostasis therapy (mechanical, thermal, injection, or combination) if active bleeding, non-bleeding visible vessel, or adherent clot is identified 1, 5
• Following successful hemostasis, initiate high-dose omeprazole: 80 mg IV bolus followed by 8 mg/hour infusion for 72 hours 1

Surgical Considerations

Indications for Emergency Surgery

• Immediate surgery is mandatory if patient has diffuse peritonitis with hemodynamic instability despite resuscitation 3
• Radiological signs of pneumoperitoneum with free fluid in an acutely unwell patient require surgical exploration 3
• Unstable patients with hemorrhagic shock non-responsive to resuscitation need immediate surgery 3
• Failed endoscopic hemostasis warrants transcatheter arterial embolization attempt, then surgery if unsuccessful 4

Special Populations at Higher Risk

• Elderly patients (>65 years) have significantly higher mortality and require more aggressive management 1
• Patients with cardiovascular, renal, or liver disease are at increased risk for complications and death 1
• Immunocompromised patients or those on immunomodulators have higher risk of intra-abdominal sepsis 3

Critical Pitfalls to Avoid

• Do not delay imaging with CT if mesenteric ischemia is suspected - this diagnosis requires emergency surgery and has devastating outcomes if missed 3
• Do not assume lower GI source based solely on "red" stool color - melena can appear dark red and upper GI bleeding is more common and dangerous 2
• Do not withhold contrast CT for renal failure concerns - the consequences of missed diagnosis far outweigh contrast nephropathy risk 3
• Recognize that inflammatory bowel disease can present with acute bleeding and diffuse pain, requiring multidisciplinary gastroenterology involvement 3

Medication Management

• Start proton pump inhibitor therapy immediately upon presentation before endoscopy 1, 4
• Administer venous thromboembolism prophylaxis with low molecular weight heparin once bleeding is controlled 3
• Avoid NSAIDs in patients with history of GI bleeding 5
• Consider antibiotic coverage only if signs of perforation, sepsis, or intra-abdominal abscess are present 3