What is the most common cause of massive lower gastrointestinal tract (GIT) bleeding in an elderly male with a history of chronic constipation and heart disease?

Most Common Cause of Massive Lower GI Bleeding in This Patient

In an elderly male with chronic constipation and heart disease presenting with massive lower GI bleeding, diverticulosis (Option B) is the most common cause.

Epidemiology and Risk Profile

Diverticulosis accounts for 21-41% of all lower GI bleeding cases and is the single most common etiology. 1 In patients over 60 years of age, the prevalence of diverticulosis reaches 50%, and this increases further with advancing age. 2

Key Risk Factors Present in This Patient:

• Age: Diverticular disease is uncommon under age 40, but by age 50, nearly one-third of the population has diverticulosis. 3
• Heart disease: Ischemic heart disease is specifically associated with diverticular hemorrhage. 3
• Likely medication use: Patients with heart disease commonly take anticoagulants or antiplatelet agents, which significantly increase the risk of severe diverticular bleeding. 2, 4
• Hypertension medications: Blood pressure medications are predictive of severe diverticular hemorrhage (p = 0.049). 5

Why Diverticulosis Over Other Options

Diverticulosis Characteristics:

• Painless bleeding: Diverticulosis characteristically presents with painless bleeding, distinguishing it from inflammatory or ischemic causes. 6
• Massive hemorrhage potential: Approximately 50% of patients with diverticular bleeding require blood transfusion, and 18-53% may need emergency surgery. 2
• Right-sided predominance in bleeding: While 90% of diverticula are in the left colon, bleeding originates from the right colon at least 50% of the time. 3

Why Not Angiodysplasia (Option A):

• Angiodysplasia accounts for only 3-40% of lower GI bleeding cases, making it less common than diverticulosis. 6
• While also painless and associated with elderly patients, it is definitively the second most common cause after diverticulosis. 6

Why Not Colonic Cancer (Option C):

• Colorectal malignancy/polyps account for only 6-27% of lower GI bleeding cases. 6
• Cancer typically presents with chronic, intermittent bleeding rather than acute massive hemorrhage. 1
• Pain is usually present only when associated with obstruction or perforation. 6

Why Not Peptic Ulcer Disease (Option D):

• This is an upper GI source, not a lower GI source. 1
• While 10-15% of patients with hematochezia have an upper GI source, the question specifically asks about lower GIT bleeding. 6

Clinical Implications for Management

Severity Predictors in This Patient:

The presence of heart disease and likely anticoagulation creates a high-risk profile. Patients on anticoagulants/antiplatelets have significantly higher rates of severe lower GI bleeding (55.1% vs 35.4%; P=0.01). 4

Initial Management Priorities:

• Hemodynamic resuscitation: Target hemoglobin >7 g/dL, or >9 g/dL in patients with cardiovascular disease or massive bleeding. 1
• Coagulopathy correction: If INR ≥1.5, this independently predicts severe diverticular hemorrhage (p = 0.003) and should be corrected with fresh frozen plasma and vitamin K. 1, 5
• Spontaneous resolution: Approximately 75-90% of diverticular bleeding episodes stop spontaneously, especially in patients requiring <4 units of blood transfusion over 24 hours. 1, 3

Common Pitfall:

Do not assume the bleeding source without endoscopic confirmation. While diverticulosis is most common, colonoscopy is required in patients using anticoagulants/antiplatelets because colorectal abnormalities (including cancer) are frequently present in this population. 4