The Medical Term for Blood in Stool Depends on What the Blood Looks Like
Quick answer: fresh or bright-red blood passed with stool is commonly called hematochezia. Black, tarry stool containing digested blood is called melena. Blood that is present but too small to see is called occult blood.
“Rectal bleeding” and “gastrointestinal bleeding” are broader clinical terms. The color, amount, symptoms and location of bleeding help a clinician decide which term is accurate.
Choose the term by appearance
Independent medical dictionary: Medical-Terms.org explains terminology for education and chart-reading. Blood in stool can have minor or serious causes, and the medical term does not diagnose the cause. New, repeated, unexplained or significant bleeding should be discussed with a healthcare professional.
What is the medical term for blood in stool?
There is no single term that accurately describes every kind of blood in stool. The correct word depends mainly on whether the blood is fresh and red, digested and black, or invisible to the eye.
Hematochezia
Fresh red or maroon blood passed through the anus, commonly seen on, in or around stool. It usually suggests lower gastrointestinal bleeding, although a very brisk upper-GI bleed can occasionally present this way.
Melena
Black, tarry, often sticky stool containing digested blood. It most often points to bleeding higher in the gastrointestinal tract, although small-bowel or right-colon bleeding can sometimes produce melena.
Occult blood
Blood present in stool in an amount too small to see. It is detected using stool testing rather than by visual inspection.
Do not choose the diagnosis from the color alone. Color gives clues but does not prove the source. Rapid upper-GI bleeding can produce red rectal blood, while bleeding farther down the intestine can sometimes become darker before it passes.
Blood in stool terms by color and pattern
| What you notice | Common medical term | What it may suggest | Important qualification |
|---|---|---|---|
| Bright-red blood on stool, paper or in toilet | Hematochezia / rectal bleeding | Often bleeding from the colon, rectum or anus | Heavy upper-GI bleeding can occasionally move rapidly enough to appear red. |
| Dark-red or maroon blood mixed with stool | Hematochezia may still be used | Can arise from farther up the colon or small bowel | Appearance cannot precisely locate the source without clinical evaluation. |
| Black, tarry, sticky stool | Melena | Often upper gastrointestinal bleeding | Iron, bismuth and some foods can darken stool without bleeding. |
| No visible blood, positive stool blood test | Occult blood | Small amounts of gastrointestinal bleeding | The test detects blood but does not identify the bleeding source. |
Medical-record wording may vary. A clinician may document “hematochezia,” “bloody stool,” “BRBPR” (bright red blood per rectum), “rectal bleeding,” “melena,” “positive FOBT/FIT,” or “GI bleed” depending on what was observed and what is known about the source.
Hematochezia vs melena vs occult blood vs rectal bleeding
| Term | Meaning | Most useful distinction |
|---|---|---|
| Hematochezia | Passage of fresh red blood through the anus, usually with or around stool. | Describes visible fresh blood rather than black digested blood. |
| Melena | Black, tarry stool containing degraded/digested blood. | Usually indicates that blood spent longer in the gastrointestinal tract. |
| Occult blood | Blood that is not visible to the naked eye. | Detected by testing rather than appearance. |
| Rectal bleeding | Blood passing from the rectum or anus. | Broad clinical description; hematochezia is one common presentation. |
| GI bleeding | Bleeding originating anywhere in the gastrointestinal tract. | Umbrella clinical category that can cause hematochezia, melena, hematemesis or occult bleeding. |
Not hematemesis
Hematemesis means vomiting blood. It describes blood coming out through the mouth rather than passing in stool.
Not hematuria
Hematuria means blood in urine. It is a urinary finding, not gastrointestinal bleeding.
What can cause blood in stool?
Blood in stool is a finding rather than a diagnosis. The cause can be close to the anus, elsewhere in the colon, in the small bowel or in the upper digestive tract. Some causes are common and relatively minor; others need prompt investigation.
Anus and rectum
- Hemorrhoids
- Anal fissure
- Proctitis
- Rectal trauma or prolapse
Colon and small bowel
- Diverticular bleeding
- Inflammatory bowel disease
- Infectious colitis
- Angiodysplasia
- Polyps or colorectal cancer
Upper gastrointestinal tract
- Peptic ulcers
- Gastritis
- Esophageal or gastric varices
- Mallory-Weiss tear
- Upper-GI tumors
Hemorrhoids are common, but visible bleeding should not automatically be blamed on hemorrhoids. NIDDK notes that rectal bleeding can also occur with inflammatory bowel disease and colon or rectal cancer, so persistent or unexplained bleeding deserves medical evaluation.
Can red or black stool occur without gastrointestinal bleeding?
Yes. Stool color is useful but not definitive. MedlinePlus notes that beets and red food coloring can make stool appear reddish. Black stool can also occur after iron supplements, bismuth-containing medicines and some foods.
Red-looking stool without blood
Foods or dyes can mimic blood. If the cause is uncertain, a healthcare professional can decide whether testing is appropriate.
Black stool without melena
Iron and bismuth may turn stool black. True melena is typically tarry and related to digested blood, but appearance alone is not always enough to be certain.
Do not stop prescribed medicine simply to “test” the stool color. If iron, bismuth, aspirin, NSAIDs or blood-thinning medicines are relevant, tell the clinician evaluating the bleeding.
How do doctors evaluate blood in stool?
The evaluation depends on the amount and color of blood, whether bleeding is ongoing, the person’s vital signs, age, medicines and other symptoms. The goal is to identify how severe the bleeding is and where it is coming from.
History and symptom pattern
A clinician may ask whether blood is bright red, maroon or black; whether it coats the stool or is mixed through it; how often it occurs; and whether there is abdominal pain, diarrhea, constipation, fever, weight loss, vomiting or dizziness.
Medication and medical-history review
NIDDK specifically notes that clinicians may ask about NSAIDs such as aspirin and about blood-thinning medicines, along with prior GI bleeding and relevant family history.
Physical examination
Vital signs, abdominal examination and sometimes a digital rectal examination can provide clues about blood loss and the likely source.
Blood and stool testing
A complete blood count and other blood tests may help show anemia or severity of blood loss. Stool tests can detect occult blood or investigate infection when appropriate.
Endoscopy or imaging
Depending on the presentation, evaluation may include anoscopy, colonoscopy, upper endoscopy, capsule endoscopy, CT imaging, angiography or another test chosen to locate the source.
The same test is not right for every person. Bright-red blood from an obvious anal fissure is evaluated differently from black tarry stool with anemia or heavy ongoing bleeding.
What does occult blood in stool mean?
Occult blood means blood that is present in stool but cannot be seen just by looking. Tests such as a fecal immunochemical test (FIT) or fecal occult blood test (FOBT) can detect small quantities of blood.
These tests are commonly used in colorectal-cancer screening for people without symptoms. A positive result means blood was detected; it does not tell where the blood came from or prove that cancer is present.
Visible bleeding is different from screening. Mayo Clinic notes that FIT/FOBT screening is not intended to replace diagnostic evaluation when someone already has symptoms such as visible blood in the stool, abdominal pain or a change in bowel habits.
When can blood in stool be an emergency?
Acute GI bleeding can sometimes become severe. NIDDK advises immediate medical help for serious acute bleeding or signs of shock.
Seek emergency medical care for severe bleeding or shock symptoms. Do not wait for an online article, stool screening test or routine appointment when someone is fainting, confused, severely weak or actively losing a large amount of blood.
Common blood-in-stool terms and abbreviations in medical records
| Chart wording | Meaning | Important context |
|---|---|---|
| Hematochezia | Fresh red blood passed per rectum | Often a lower-GI finding, but source still requires evaluation. |
| BRBPR | Bright red blood per rectum | A shorthand description of visible fresh rectal blood. |
| Melena | Black tarry stool containing digested blood | Often associated with upper-GI bleeding. |
| FOBT | Fecal occult blood test | Looks for blood that cannot be seen. |
| FIT | Fecal immunochemical test | A stool test commonly used for colorectal-cancer screening. |
| GI bleed / GIB | Gastrointestinal bleeding | Broad term; source may be upper, small bowel or lower GI tract. |
Medical codes for hematochezia, melena and GI bleeding
Controlled medical vocabularies assign identifiers to these concepts. These codes describe terminology and should not be assumed to be the correct insurance or billing diagnosis for an individual patient.
| System | Code | Concept | Source meaning |
|---|---|---|---|
| SNOMED CT | 405729008 | Hematochezia / blood in stool | Fresh or bright-red blood passed per anus/in stool. |
| SNOMED CT | 2901004 | Melena | Black, tarry stool containing altered/digested blood. |
| MeSH | D006471 | Gastrointestinal Hemorrhage | Bleeding in the gastrointestinal tract; hematochezia appears as an entry term. |
| MeSH | D008551 | Melena | Black, tarry, foul-smelling feces containing degraded blood. |
Coding distinction: terminology identifiers such as SNOMED CT or MeSH help describe concepts consistently. Clinical billing codes depend on the documented diagnosis, bleeding source, encounter and coding system in use.
Common mistakes when interpreting blood in stool
Calling all blood hematochezia
Hematochezia specifically refers to fresh red blood. Black tarry blood is more accurately called melena, while hidden blood is occult blood.
Assuming hemorrhoids are always the cause
Hemorrhoids commonly bleed, but inflammatory bowel disease, diverticular disease, polyps, cancer, ulcers and other conditions can also cause GI bleeding.
Using a screening test for visible bleeding
FIT and FOBT are useful screening tools, but visible symptomatic bleeding should be assessed clinically rather than treated as a routine screening question.
Another mistake is treating black stool as automatically melena. Iron, bismuth and foods can darken stool. The complete appearance, medication history and clinical context matter.
Authoritative references used for this refresh
Blood in stool medical term FAQs
What is the medical term for bright red blood in stool?
Hematochezia is the common medical term for fresh or bright-red blood passed through the anus, often in or with stool.
What is the medical term for black blood in stool?
Melena means black, tarry stool containing digested or degraded blood. It often points to an upper gastrointestinal bleeding source.
What is occult blood in stool?
Occult blood is blood that is present in stool but cannot be seen with the naked eye. Tests such as FIT or FOBT can detect it.
Is rectal bleeding the same as hematochezia?
They overlap, but rectal bleeding is the broader phrase. Hematochezia specifically describes passage of fresh red blood through the anus.
Does bright red blood always come from hemorrhoids?
No. Hemorrhoids are a common cause, but anal fissures, inflammation, diverticular disease, infections, polyps, colorectal cancer and other problems can also cause bleeding.
Can an upper GI bleed cause bright red blood in stool?
Yes, although it is less common. A brisk upper gastrointestinal bleed can move through the bowel rapidly enough to produce hematochezia rather than melena.
Can black stool occur without bleeding?
Yes. Iron supplements, bismuth-containing medicines and some foods can turn stool dark or black. True melena is generally tarry and associated with digested blood.
What does BRBPR mean?
BRBPR means bright red blood per rectum. It is chart shorthand for visible fresh red rectal bleeding.
Should I use an at-home FIT or FOBT if I can already see blood?
Visible blood is a symptom rather than a routine screening situation. A healthcare professional should decide the appropriate evaluation instead of relying on a screening stool test to identify the cause.
When is blood in stool an emergency?
Seek urgent medical help for heavy or ongoing bleeding, fainting, confusion, severe weakness, shock symptoms, vomiting blood, black tarry stool with dizziness, or other signs of significant blood loss.
How this blood-in-stool terminology page was rebuilt
Medical information note: blood in stool is a sign or symptom, not a final diagnosis. The appropriate evaluation depends on age, amount of bleeding, stool appearance, medicines, medical history and associated symptoms.