Blood in Stool
Many conditions can cause blood in stool, from minor problems like hemorrhoids or anal fissures to more serious issues such as inflammatory bowel disease, diverticulosis, polyps, or even colorectal cancer. Infections, ulcers, or irritation from constipation are also common reasons. Even stress can sometimes play a role.
The color and amount of blood can give clues. Bright red blood often comes from the lower part of the digestive tract, while darker blood or black stool might mean bleeding higher up. If you notice blood in your stool, pay attention to other symptoms like pain, weight loss, or changes in bowel habits, as these may signal a more serious problem.
Definition of Symptom
Blood in stool means you notice blood in your bowel movements. It may show as red streaks, spots, or a darker color mixed with stool. This symptom is also called rectal bleeding. Sometimes, blood makes the stool look very dark or even black.
These tarry stools can signal bleeding higher up in the digestive tract. Blood in the stool is not an illness by itself, but a sign that something may be wrong in the digestive system. Possible appearances of blood in stool:
| Appearance | Possible Meaning |
|---|---|
| Bright red | Lower colon, rectum, or anus bleeding. |
| Dark or black | Potential bleeding in the upper digestive tract. |
| Red streaks | Small tears, hemorrhoids, or minor injury. |
| Tarry stool | Bleeding in stomach or small intestine. |
You might see blood in the toilet bowl, on toilet paper, or mixed with the stool. Not every case is easy to see—sometimes, blood is hidden and only found with a stool test.
Possible Causes/Diseases Condition
Many things can cause blood in stool. Some are minor, while others are more serious. Hemorrhoids commonly cause blood in stool. Swollen veins in the rectum or anus can bleed, especially during bowel movements. Anal fissures are small tears in the lining of the anus. They can cause bright red blood on toilet paper or in the toilet.
Colon polyps are growths on the inner lining of the colon. Some polyps bleed and may need removal because they can turn into cancer over time. Inflammatory bowel disease (IBD) includes Crohn’s disease and ulcerative colitis. These conditions cause inflammation in the digestive tract, leading to bleeding, cramping, and diarrhea.
Colitis means inflammation of the colon. Infections, IBD, or reduced blood flow can cause colitis and lead to blood in stool. Infections like gastroenteritis can also cause bloody stools. Bacteria, viruses, or parasites may be responsible. More serious causes include colorectal cancer and colon cancer. Bleeding from cancer can appear as blood in the stool or make the stool look dark and tarry.
Diverticulosis causes small pouches to form in the colon wall, which can bleed. This is more common in older adults. Ulcers in the stomach or upper digestive tract can also cause bleeding that may show up in the stool.
| Cause | Possible Symptoms |
|---|---|
| Hemorrhoids | Bright red blood, pain with stools |
| Anal fissures | Bright red blood, pain during BM |
| Colon polyps | Blood in stool (often painless) |
| IBD (Crohn’s, Ulcerative Colitis) | Cramping, diarrhea, bleeding |
| Colorectal/Colon cancer | Blood in stool, changes in bowel habits |
| Diverticulosis | Sudden, painless bleeding |
| Infections (Gastroenteritis) | Diarrhea, fever, blood in stool |
| Ulcers | Black/tarry or bloody stool, stomach pain |
Any presence of blood in stool should be checked by a healthcare provider to find the exact cause.
Other Non-Disease Causes
Not all blood in stool means there is a disease. Some causes relate to daily habits, diet, or medicines. Constipation is a common cause, especially if you strain hard during bowel movements. Straining can cause small tears or irritation in the rectum, leading to small amounts of blood.
Diarrhea and vomiting can sometimes irritate the anal area. This irritation makes the skin around the anus more likely to bleed, especially if you wipe often or too hard. Certain foods can make stool appear red, which might look like blood. Examples include:
- Beets
- Red food coloring
- Tomato soup
A simple table explains food causes:
| Food/Drink | Possible Effect |
|---|---|
| Beets | Red/pink stool |
| Red gelatin/candy | Red stool |
| Tomato soup/sauce | Orange-red stool |
Medicines and supplements can also play a part. Iron supplements sometimes turn stool dark or cause mild irritation that leads to bleeding. Blood thinners make it easier for any minor injury in the bowel or anus to bleed.
Food poisoning may cause diarrhea that can make the anus sore, and in some cases, tiny blood streaks might appear. Look for patterns. If blood in stool only happens after eating certain foods or while taking supplements, it may not be serious. However, if bleeding continues, see a doctor.
How It Causes the Symptom
Blood appears in the stool when bleeding happens somewhere along the digestive system, which includes the esophagus, stomach, small intestine, and large intestine. Bleeding in the upper digestive tract—like the esophagus or stomach—often makes the stool look black or tarry.
Bleeding from the lower parts, such as the large intestine or rectum, usually looks red or maroon. Hemorrhoids, anal fissures, or conditions affecting the colon often cause this. Doctors use colonoscopy or endoscopy to find where the bleeding starts. These tools let them look inside the bowel and other areas of the digestive tract.
Sometimes, people feel abdominal pain with blood in their stool. This can signal inflammation or injury in the small or large intestine. Here’s a quick look at some causes by location:
| Location | Example Causes | Stool Appearance |
|---|---|---|
| Esophagus/Stomach | Ulcers, gastritis | Black, tarry |
| Small Intestine | Crohn’s, infections | Dark or mixed |
| Large Intestine | Polyps, cancer, colitis | Bright red or maroon |
Doctors may order tests like bloodwork or stool studies to help uncover anemia, infection, or signs of ongoing bleeding.
Possible Complications
Blood in the stool can lead to health issues if not treated. One main risk is anemia, which happens when you do not have enough healthy red blood cells due to ongoing blood loss. You may also feel fatigue because your body is not getting enough oxygen from your blood. This tired feeling can affect daily life and make even simple activities hard.
Some people notice nausea or a loss of appetite. These symptoms can make it difficult to eat well, and over time, this might result in unexplained weight loss. A serious concern is if bleeding comes from diseases like cancer or inflammatory bowel disease. Without proper care, these conditions can become harder to treat.
Table: Common Complications
| Complication | Description |
|---|---|
| Anemia | Low red blood cells from blood loss. |
| Fatigue | Weakness and tiredness. |
| Nausea | Upset stomach and less appetite. |
| Weight Loss | Losing weight for no clear reason. |
Severe blood loss can sometimes require a hospital visit or a blood transfusion. The cause of the bleeding affects the risk of each complication, so seeing a doctor for testing is important.
When to Seek Medical Attention
It is important to know when to contact a doctor if there is blood in the stool. Sometimes the cause can be minor, but it can also be a sign of a serious problem. See a doctor if the bleeding is heavy, continuous, or comes with severe abdominal pain or cramping. Seek help if blood in the stool lasts more than a day or two, or if it is making you anxious. Call for urgent medical care if any of these symptoms appear:
- Fever or severe weakness
- Dizziness or fainting
- Bloody diarrhea that starts suddenly
- Cold, sweaty, or clammy skin
- Fast heart rate
- Passing more than one cup of blood
A doctor may suggest a rectal exam or stool tests to help find the cause. These tests can look for infections, bowel disease, or signs of cancer. People with other symptoms, like changes in bowel movements, unexplained weight loss, or tiredness, should not delay seeing a doctor.
