Specific History Questions and Physical Examination Findings for Lower GI Fresh Bleed Differential Diagnoses
A systematic approach to history and physical examination should focus on identifying specific clinical features that distinguish between the major causes of acute lower gastrointestinal bleeding, with age, medication history, and associated symptoms being the most discriminating factors 1.
Key History Questions by Differential Diagnosis
Diverticular Bleeding
- Age >70 years (most predictive factor) 1
- Painless bleeding - typically sudden onset of bright red blood
- History of constipation or known diverticulosis
- NSAID use 1
- Aspirin or anticoagulant use
Angiodysplasia
- Age >70 years 1
- Painless bleeding - often intermittent, chronic episodes
- History of chronic kidney disease
- History of aortic stenosis or other cardiac valvular disease
- Anticoagulant or antiplatelet medication use 1
Ischemic Colitis
- Abdominal pain (crampy, left-sided) preceding or accompanying bleeding 1
- History of cardiovascular disease, atrial fibrillation
- Recent hypotensive episode or cardiac surgery
- Medications: NSAIDs, cocaine use
- Age >60 years
Inflammatory Bowel Disease (IBD)
- Diarrhea with blood 1
- Abdominal pain 1
- Weight loss 1
- Fever 1
- Previous IBD diagnosis or family history
- Young to middle-aged patients (though can occur at any age)
Infectious Colitis
- Diarrhea (often bloody) 1
- Fever 1
- Abdominal pain 1
- Recent antibiotic use (C. difficile)
- Travel history
- Food exposure history
- Immunocompromised state
Colorectal Malignancy
- Weight loss 1
- Change in bowel habits 1
- Symptoms of partial obstruction 1
- Age >50 years
- Family history of colorectal cancer
- Personal history of polyps or IBD
Hemorrhoids
- Bright red blood on toilet paper or coating stool
- History of straining, constipation
- Anal pain or discomfort (if thrombosed) 2
- Painless if uncomplicated
Radiation Proctitis
- History of pelvic radiation therapy (prostate or gynecologic cancer) 1
- Timing: 9 months to 4 years post-radiation 1
- Chronic, intermittent bleeding
- Tenesmus, urgency
Post-Polypectomy Bleeding
- Recent colonoscopy with polypectomy (within 2 weeks)
- Particularly after piecemeal polypectomy of large polyps
Essential Physical Examination Findings
Hemodynamic Assessment
- Orthostatic vital signs (heart rate increase >20 bpm or BP drop >20 mmHg systolic) 1
- Tachycardia 1
- Tachypnea 1
- Hypotension (indicates severe bleeding) 1
- Shock index >1 (heart rate/systolic BP) indicates need for urgent intervention 3
General Appearance
- Pallor 1
- Signs of chronic liver disease (spider angiomata, palmar erythema, jaundice) - suggests portal hypertension
- Cachexia - suggests malignancy
Abdominal Examination 1
- Tenderness - suggests ischemic colitis, IBD, infectious colitis, or perforation
- Peritoneal signs - suggests perforation or severe ischemia
- Distension - suggests obstruction (malignancy)
- Palpable mass - suggests malignancy
- Hepatosplenomegaly - suggests portal hypertension
Digital Rectal Examination 1, 2
This is mandatory in all patients 1
- Confirm presence and appearance of blood (bright red vs. dark vs. melena) 1
- Palpable rectal mass - 40% of rectal carcinomas are palpable 1
- Hemorrhoids - external or internal (may require anoscopy)
- Anal fissure - painful, visible tear
- Perianal abscess or fistula
- Stool color and consistency
Cardiac and Pulmonary Examination 1
- Cardiac murmurs (aortic stenosis associated with angiodysplasia)
- Signs of heart failure
- Respiratory distress
Critical Discriminating Features
Pain vs. Painless Bleeding
- Painless bleeding strongly suggests diverticulosis or angiodysplasia 1
- Pain with bleeding suggests ischemic colitis, IBD, infectious colitis, or malignancy 1
Age Stratification
- Age >70 years: Diverticulosis and angiodysplasia are most likely 1
- Age <50 years: IBD, infectious colitis, hemorrhoids more likely
- Age 50-70 years: Broader differential including malignancy
Medication History 1
- NSAIDs: Diverticular bleeding, ischemic colitis, ulceration
- Anticoagulants/antiplatelets: Any source more likely to bleed significantly
- Recent antibiotics: C. difficile colitis
Common Pitfalls to Avoid
Assuming hemorrhoids without examination: Always perform digital rectal exam and consider anoscopy/proctoscopy 3 - hemorrhoids are often incidental findings, not the bleeding source
Missing upper GI source: 10-15% of severe hematochezia originates from upper GI tract 1 - consider nasogastric lavage if suspicion exists
Underestimating severity: Orthostatic vital signs and shock index are more sensitive than resting vitals alone 1, 3
Overlooking medication-induced bleeding: Always document anticoagulants, antiplatelets, and NSAIDs 1
Failing to assess coagulopathy: Check INR and platelet count in all patients 1