What are the steps for evaluating a patient with intermittent abdominal discomfort and dark stools?

Evaluation of a 36-Year-Old Male with Intermittent Abdominal Discomfort and Dark Stools

This patient requires immediate investigation for upper gastrointestinal bleeding, as dark stools (melena) strongly suggest a bleeding source above the ligament of Treitz and necessitates urgent assessment to prevent morbidity and mortality. 1, 2

Immediate Clinical Assessment

History Taking - Critical Red Flag Features

• Confirm the nature of dark stools: True melena (black, tarry, foul-smelling) has a likelihood ratio of 5.1-5.9 for upper GI bleeding, while melenic stool on examination increases this to LR 25 2
• Assess for hematemesis or coffee-ground emesis, which are pathognomonic for upper GI bleeding 1, 3
• Document hemodynamic symptoms: Lightheadedness, syncope, or palpitations suggest significant blood loss 1
• Quantify abdominal pain characteristics: Location (epigastric vs diffuse), relationship to meals, and duration 4
• Screen for NSAID use, aspirin, anticoagulants, or alcohol excess, as these are major risk factors for gastroduodenal bleeding 4
• Exclude recent fish bone or foreign body ingestion, which can cause occult duodenal ulceration 3

Physical Examination

• Vital signs are critical: Tachycardia (heart rate >100) has LR 4.9 for severe upper GI bleeding requiring urgent intervention 2
• Perform digital rectal examination to confirm melena and exclude blood clots in stool (which would suggest lower GI source with LR 0.05 for upper GI bleeding) 2
• Assess for peritoneal signs (guarding, rebound tenderness) which would indicate perforation requiring emergency surgery 5

Essential Laboratory Investigations

Order immediately upon presentation:

• Complete blood count: Hemoglobin <8 g/dL has LR 4.5-6.2 for severe bleeding requiring urgent intervention 2
• Blood urea nitrogen and creatinine: BUN:creatinine ratio >30 has summary LR 7.5 for upper GI bleeding 2
• Coagulation studies (PT/INR, PTT) to assess bleeding risk and guide transfusion 1
• Type and crossmatch for potential blood product administration 1
• Liver function tests and lipase to evaluate for hepatobiliary or pancreatic pathology 6

Risk Stratification Using Blatchford Score

Calculate the Blatchford score immediately - this does not require nasogastric lavage and is highly efficient for risk stratification 2:

• A Blatchford score of 0 has summary LR 0.02 for requiring urgent intervention, allowing safe outpatient management 2
• Scores ≥1 indicate need for admission and urgent endoscopy 2

Resuscitation and Initial Management

If hemodynamically unstable or hemoglobin <8 g/dL:

• Initiate IV crystalloid resuscitation with two large-bore IV lines 1
• Transfuse packed red blood cells to maintain hemoglobin >7 g/dL (or >8 g/dL if cardiovascular disease) 1
• Start high-dose intravenous proton pump inhibitor (e.g., pantoprazole 80 mg IV bolus, then 8 mg/hour infusion) immediately to decrease probability of high-risk stigmata at endoscopy 1

Endoscopic Evaluation

Upper endoscopy (esophagogastroduodenoscopy) should be performed within 24 hours of presentation after initial stabilization 1:

• This is the definitive diagnostic and therapeutic intervention for non-variceal upper GI bleeding 1
• Consider prokinetic agent (e.g., erythromycin 250 mg IV) 30-60 minutes before endoscopy to improve visualization 1
• Endoscopy allows identification of bleeding source and therapeutic intervention (injection, thermal, or mechanical hemostasis) 1

Alternative Diagnoses to Consider in This Age Group

If initial workup for GI bleeding is negative, consider:

• Functional dyspepsia: Most common cause of dyspepsia in patients <40 years without alarm features, but dark stools make this diagnosis unlikely until bleeding excluded 4
• H. pylori infection: Test with breath or stool antigen testing if endoscopy not immediately performed 4
• Medication-induced gastropathy: NSAIDs are strongly associated with dyspepsia and can cause occult bleeding 4

Critical Pitfalls to Avoid

• Do not attribute dark stools to dietary causes (iron supplements, bismuth, black licorice) without excluding true melena through stool examination 2
• Do not delay endoscopy based on normal vital signs - compensated patients can deteriorate rapidly 1
• Do not perform nasogastric lavage routinely - it adds little diagnostic value beyond clinical assessment and Blatchford scoring, and the Blatchford score without lavage is more efficient 2
• At age 36, this patient is below the threshold for urgent cancer screening, but do not dismiss symptoms if they persist or worsen after treatment 4

Follow-Up After Acute Management

If endoscopy reveals peptic ulcer disease:

• Test for H. pylori and treat if positive 4
• Continue PPI therapy for 4-8 weeks 1
• Discontinue NSAIDs permanently if possible 4

If no bleeding source identified and symptoms persist:

• Consider full blood count in patients aged ≥25 years 4
• Evaluate for celiac disease with serology if diarrhea present 6
• Reassess in 3-6 weeks, and escalate investigation if alarm features develop 6