creation date: 2025-11-10 13:54
tags: Workups
Rectal Bleeding
Background
Hematochezia or rectal bleeding refers to bleeding from the gastrointestinal tract that can be appreciated from the rectum. This can range from large, volume bleeds to mild cases involving streaking in stool or on toilet paper after wiping.
Pathophysiology
Generally, rectal bleeding involves rupturing or damage to the vasculature within the gastrointestinal tract.
In cases of upper GI bleed, gastric and duodenal secretions convert hemoglobin to acid hematin resulting in a darker, reddish-brown colour. This contrasts to lower GI bleeding, which typically presents with bright, red blood.
The division of upper and lower GI is the ligament of Tritz (suspensory ligament of the duodenum).
Differential Diagnosis
Lower GI bleed:
- Colorectal cancer
- Colon polyps (incl. adenomas)
- Inflammatory bowel disease
- Diverticular disease
- Hemorrhoids
- Anal fissures
- Infectious colitis
- Infections (eg. STI)
- Ischemic colitis
- Angiodysplasia
- NSAID-induced colitis
Upper GI bleed:
- Mallory Weiss tear
- Bleeding esophageal varicies
- Perforated gastroduodenal artery
Initial Evaluation
History
A detailed history should be conducted to determine etiology.
- Onset
- Amount
- Frequency
- Passage of clots
- Bright red vs maroon/tarry
Associated symptoms include:
- Abdominal pain
- Weight loss
- Change in bowel habits
- Hematemesis
- PMHx of pelvic surgery or abdominal-pelvic radiation
- Signs of trauma
- STI-related symptoms
- Anal pain
Underlying factors that may contribute to the presentation include:
- Vitamin K deficiency
- Hemophilia
- Thrombocytopenia
- Anti-coagulant and NSAIDs use
Physical Exam
Initial assessment should be on hemodynamic status.
Examination should include:
- Abdominal exam - masses, pain, distension, signs of cirrhosis
- Perineum inspection - for blood, thrombosed vessels, prolapsing hemorrhoids, fissures, protruding masses
- Rectal exam - hemorrhoids, skin tags, fissures, masses and internal hemorrhoids
Investigations
Initial evaluation includes:
- CBC
- Coagulation panel
- STI testing suspected
In patients older than age of 40, endoscopy is indicated and is the gold standard. If unavailable or contraindicated, or if there is large volume of bleeding, CT angiography may be indicated.