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Clinical Symptom🐕 Dogs🐈 Catsgastrointestinal

Hematochezia

🗣️ Pronounced:hee-mat-oh-KEE-zee-uh
In One Sentence (Plain English)

The passage of fresh, bright red blood in or on the stool, originating from the lower gastrointestinal tract (colon, rectum, or anus).

Editorial Status: Verified from peer-reviewed veterinary sources (v1.0)
Updated: 2026-01-15

💬 In Plain English

Unlike black digested blood (melena), hematochezia is fresh, bright red, frank blood seen in the stool. Because it comes from the lower bowel (the colon, rectum, or anal glands), it has not been digested by stomach acid. Owners often see streaks of red blood on the outside of formed feces, or liquid diarrhea that looks like raspberry jam mixed with clear slime (mucus). While alarming to see, common mild causes like colitis or dietary indiscretion are far more frequent than severe life-threatening conditions.

🔬 Clinical & Technical Depth

For Vets & Technicians

Formal Clinical Definition

Passage of gross, bright red blood (frank blood) per rectum. Differentiates from melena by indicating bleeding distal to the ileocecal valve, most commonly from colorectal inflammation, erosion, polyps, or trauma.

Why Veterinarians Use It

Veterinarians assess hematochezia to localize gastrointestinal disease to the large bowel (colitis) rather than the stomach or upper small intestine.

Clinical Context Encountered

Very common in dogs after eating foreign objects, stress colitis from boarding, whipworm infections, or acute hemorrhagic diarrhea syndrome (AHDS).

Clinical Reference Guide (Clinical Symptom)

Urgency Level

🚨 Red Flag Warnings (When to Contact an Emergency Vet)
  • •Sudden, massive "raspberry jam" diarrhea accompanied by profound lethargy and dehydration suggests Acute Hemorrhagic Diarrhea Syndrome (AHDS), requiring urgent IV fluid therapy to prevent hypovolemic shock.

❓ Questions to Ask Your Veterinarian

Take these actionable questions with you to your next clinic visit or appointment:

  • 1Is the red blood streaked on formed stool (focal rectal/anal issue) or mixed into liquid diarrhea (colitis)?
  • 2Did a fecal flotation or antigen test detect parasites like whipworms, giardia, or hookworms?
  • 3Could stress colitis or acute hemorrhagic diarrhea syndrome (AHDS) be responsible?
  • 4What bland, low-residue or high-fiber diet will allow the colon lining to heal?

Academic & Clinical References