Why Hemorrhoidal Blood Appears Brick Red
Hemorrhoidal bleeding produces bright red (brick red) blood because hemorrhoids originate from arteriovenous plexuses with direct arterial supply in the anal canal, resulting in fresh, oxygenated blood that has not undergone digestion or oxidation in the gastrointestinal tract. 1
Anatomic and Vascular Basis
Hemorrhoids represent abnormal swelling of anal cushions with dilation of the submucosal arteriovenous plexus, which contributes 15-20% of resting anal pressure 1
The hemorrhoidal venous plexus receives direct arterial blood flow, meaning the blood is oxygen-rich and has not been exposed to digestive enzymes or gastric acid that would darken it 1
Internal hemorrhoids originate above the dentate line and when they bleed, the blood travels a very short distance to exit the body, preventing oxidation or color change 2
Clinical Presentation Characteristics
Hemorrhoidal bleeding typically presents as bright red blood that may drip or squirt into the toilet bowl, distinguishing it from occult bleeding or melena 3
The blood is associated with bowel movements and appears on toilet paper, in the bowl, or coating the stool surface 2
This bright red appearance contrasts sharply with upper GI bleeding (which produces black, tarry melena due to hemoglobin oxidation by gastric acid) or bleeding from more proximal colonic sources 3
Critical Clinical Pitfall
Never attribute a positive fecal occult blood test (Hemoccult) to hemorrhoids without complete colonic evaluation, as hemorrhoidal bleeding produces visible bright red blood, not occult blood 3
When bright red bleeding is atypical for hemorrhoids or a positive Hemoccult test is present, complete colonoscopy or air-contrast barium enema is mandatory to exclude proximal pathology 3
Anemia from hemorrhoidal disease is rare (0.5 patients per 100,000 population), so significant anemia warrants investigation for alternative bleeding sources 3