The difference between melena (black stool) and hematochezia (bloody stool) lies in stool color and bleeding location, serving as key indicators for gastrointestinal bleeding. This article explains definitions, causes, symptoms, and responses based on official medical information.

Basic Definitions

Melena refers to black, tarry stool where blood reacts with stomach acid to form hematin. Hematochezia is bright red or dark red blood mixed in stool, indicating bleeding near the anus.

These symptoms help estimate digestive tract bleeding sites. Melena suggests upper GI bleeding, hematochezia lower GI, though exceptions occur based on bleeding volume and transit time.

Differences by Bleeding Location

Melena Features

Melena results from bleeding in the esophagus, stomach, or duodenum, turning black during digestion. It appears shiny with a foul odor and may cause anemia in large amounts.

Hematochezia Features

Hematochezia stems from lower GI bleeding in the colon, rectum, or anus, retaining red color. Blood may coat stool, redden toilet water, or appear as streaks on toilet paper.

The distinction arises from digestion extent. Upper bleeding stays longer in the gut, darkening; lower bleeds exit quickly, staying red.

Major Cause Comparison

Melena main causes include gastric ulcers, gastritis, esophageal varices, and stomach cancer from upper GI issues. Hematochezia main causes are hemorrhoids, anal fissures, colitis, colon cancer, and diverticular bleeding from lower GI.

Melena can also result from indigestion drugs or excess iron supplements (non-bleeding). Hematochezia from inflammatory bowel diseases or polyps.

Melena raises stomach concerns, hematochezia anal/colon issues. Food or drugs may mimic symptoms, requiring accurate diagnosis. Causes vary individually; check official public health sources for updates.

Accompanying Symptoms and Danger Signs

Melena with dizziness, pallor, vertigo, or vomiting blood suggests upper bleeding anemia. Hematochezia may include abdominal pain, diarrhea, weight loss.

Seek immediate care for:

• Massive bleeding (red toilet water or persistent melena)
• Shock signs (fainting, breathing difficulty)
• Ongoing pain or fever

These indicate emergencies, but leave judgment to professionals.

Common Misconceptions and Precautions

Mistake melena for just iron supplements or black foods. Rule out real bleeding; test if persistent.

Don’t assume all hematochezia is hemorrhoids. It may signal early colon cancer. Prevent constipation, eat balanced; avoid self-diagnosis.

Follow public health guidance if symptoms persist after checking diet/drugs.

Must-Check Before Melena/Hematochezia Action

If observing melena or hematochezia, verify via official government/public sites:

• Symptom duration and amount (trace vs. heavy)
• Accompanying symptoms (pain, dizziness, weight change)
• Recent food/drug history (iron, NSAIDs)
• Family history (GI/colorectal cancer)

Use this for medical visits; review latest guidelines on public portals. Consult experts as cases vary.

Next Steps for Melena/Hematochezia Observation

Having understood differences, photograph/record stool and symptoms immediately. Follow official public health updates for proper tests.

Self-care (diet) is temporary; endoscopy needed for cause. Info may change with policy; check regularly.

FAQ

Is melena always bleeding?

Melena strongly suggests upper GI bleed but iron/food can mimic. Test if ongoing.

How to tell if hematochezia is hemorrhoids?

Trace blood on paper with pain likely hemorrhoids; mixed in stool suggests colon issues. See doctor.

Can melena and hematochezia occur together?

Possible but rare by location/volume. Needs pro diagnosis for complexes.

When to go to ER?

Massive bleed, shock, persistence: emergency. Delays risk complications.

Prevention tips?

Balanced diet, avoid constipation, regular checkups. Verify guidelines if risks.