Internal Medicine · Year 3 · from Internal Medicine
Case 2: Lower GI Bleeding - Diverticular Hemorrhage
Patient Presentation
A 72-year-old woman presents with large volume bright red blood per rectum that started 3 hours ago. She has passed three bowel movements of predominantly blood with clots. She denies abdominal pain, nausea, or vomiting. Past medical history includes hypertension, diverticulosis found on colonoscopy 5 years ago, and atrial fibrillation for which she takes apixaban.
Vital Signs
- Blood Pressure: 105/68 mmHg
- Heart Rate: 102 bpm
- Respiratory Rate: 18/min
- Oxygen Saturation: 98% on room air
- Temperature: 37.0°C
Physical Examination
- General: Alert, pale
- Cardiovascular: Irregularly irregular rhythm
- Abdomen: Soft, non-tender, no masses
- Rectal exam: Gross blood, no masses
Laboratory Results
- Hemoglobin: 9.2 g/dL (baseline 12.8)
- Platelets: 198,000/μL
- BUN: 18 mg/dL
- Creatinine: 0.9 mg/dL
- INR: 1.8 (on apixaban)
Clinical Image
Figure 2: Colonoscopic image showing a diverticulum with stigmata of recent bleeding, the most common cause of significant lower GI bleeding in elderly patients.
Image Source: Educational illustration for teaching purposes.
Questions
- How does lower GI bleeding typically differ from upper GI bleeding in presentation?
- A) Always painless
- B) Hematochezia (bright red blood), usually painless, BUN/Cr ratio normal
- C) Always associated with abdominal pain
- D) Always requires surgery
- What is the most common cause of significant lower GI bleeding in elderly patients?
- A) Hemorrhoids
- B) Colorectal cancer
- C) Diverticular hemorrhage
- D) Angiodysplasia
- How should anticoagulation be managed in this patient?
- A) Continue apixaban
- B) Hold anticoagulation, consider reversal agent (andexanet alfa) if severe bleeding
- C) Switch to warfarin
- D) Give additional anticoagulation
- What is the role of colonoscopy in lower GI bleeding?
- When is angiography or surgery indicated for lower GI bleeding?
Answers
- B) Hematochezia (bright red blood), usually painless, BUN/Cr ratio normal - Lower GI bleeding presents with bright red blood or maroon stool. BUN is typically not elevated (no protein digestion). Note: Brisk upper GI bleeding can also present with hematochezia.
- C) Diverticular hemorrhage - Diverticular bleeding is the most common cause of major lower GI bleeding in elderly patients. Bleeding occurs when a vessel in the diverticulum wall (vasa recta) erodes. Most (80-85%) stop spontaneously.
- B) Hold anticoagulation, consider reversal agent (andexanet alfa) if severe bleeding - For significant bleeding, anticoagulants should be held. Reversal agents (andexanet alfa for factor Xa inhibitors, idarucizumab for dabigatran) may be considered for life-threatening bleeding. Restart anticoagulation once bleeding controlled, weighing thrombotic risk.
- Role of colonoscopy in lower GI bleeding:
- Diagnostic: Identifies source in majority of cases
- Therapeutic: Can treat bleeding with clips, thermal therapy, or injection
- Timing: Within 24 hours after adequate bowel prep for hospitalized patients
- Urgent colonoscopy (within 12 hours) has not shown improved outcomes over standard timing
- Requires bowel preparation for adequate visualization
- Indications for angiography or surgery:
- CT angiography: If massive bleeding (≥0.5 mL/min) precluding colonoscopy
- Conventional angiography: If CTA shows active extravasation - allows embolization
- Surgery: Refractory bleeding despite endoscopic and angiographic intervention
- Consider surgery earlier if transfusion requirement >6 units in 24 hours