Understanding the possible causes of blood during bowel movement, recognising warning signs and knowing when to consult a gastroenterologist can help ensure that the underlying problem is identified and treated appropriately.
Blood in stool refers to visible or hidden bleeding somewhere along the gastrointestinal tract. The blood may appear:
Bright red blood often indicates bleeding from the lower part of the digestive tract, such as the anus or rectum. Black, tarry stools can indicate bleeding higher up in the digestive tract.
However, stool colour alone cannot confirm the source of bleeding. A medical evaluation may be needed to determine the cause.
Piles, also known as haemorrhoids, are swollen blood vessels around the anus or lower rectum. They are one of the common causes of bright red rectal bleeding.
Bleeding from piles may occur during or after passing stool and may appear as blood on toilet paper, on the surface of the stool or in the toilet bowl.
Other symptoms can include:
An anal fissure is a small tear in the lining of the anus. It can develop after passing a hard or large stool, particularly in people who experience constipation.
Typical symptoms include:
Passing hard stools or straining during bowel movements can irritate or injure the anal tissues. This may result in small amounts of bleeding.
Constipation can also contribute to piles and anal fissures, creating a cycle of hard stools, straining and recurrent bleeding.
Increasing fibre and fluid intake, maintaining physical activity and addressing the underlying cause of constipation can help many people. Persistent bleeding, however, should not be ignored.
Certain intestinal infections can cause diarrhoea, abdominal cramps and blood in the stool.
Bloody diarrhoea may occur with bacterial infections and should be medically assessed, particularly when it is accompanied by fever, significant abdominal pain, dehydration or persistent symptoms.
Treatment depends on the underlying infection, so self-medication with antibiotics is not advisable without medical guidance.
Inflammatory bowel diseases such as ulcerative colitis and Crohn’s disease can cause inflammation within the digestive tract.
Depending on the affected area, symptoms may include:
Polyps are growths that develop on the inner lining of the colon. Some polyps can bleed without causing obvious symptoms.
Certain types of colon polyps can develop into colorectal cancer over time. Finding and removing potentially precancerous polyps during appropriate screening can help reduce this risk.
This is one reason why unexplained or persistent rectal bleeding should not automatically be assumed to be piles.
Colorectal cancer can sometimes cause bleeding from the rectum or changes in stool.
Possible colon cancer symptoms include:
Bleeding can also occur due to conditions such as diverticular disease, certain vascular abnormalities, ulcers and other gastrointestinal disorders.
The location and severity of bleeding can vary, which is why identifying the underlying cause is more important than treating the visible symptom alone.
Bright red blood is commonly associated with bleeding closer to the anus or lower digestive tract. Piles and anal fissures are possible causes.
However, other conditions can also produce bright red bleeding.
Dark red or maroon blood may indicate bleeding from higher in the colon or another part of the digestive tract. It should be evaluated, particularly when the bleeding is significant or recurrent.
Black, sticky or tar-like stool can indicate bleeding from the upper gastrointestinal tract. Certain foods, supplements and medications can also change stool colour, so the appearance should be interpreted in context.
If you notice black, tarry stools without an obvious explanation, seek medical advice promptly.
A single small episode of bleeding may not always indicate a serious problem. However, certain situations should prompt medical evaluation.
Consult a doctor if:
The appropriate evaluation depends on your age, symptoms, medical history and risk factors.
Heavy or ongoing bleeding requires urgent medical attention.
Seek immediate medical care if rectal bleeding is accompanied by:
These symptoms may indicate substantial gastrointestinal bleeding or another condition requiring urgent treatment.
No.
This is an important distinction because piles are a common cause of rectal bleeding, but they are not the only cause.
For example, a person may notice bright red blood and assume it is haemorrhoids. If the bleeding continues or occurs alongside changes in bowel habits, weight loss, abdominal pain or anaemia, another underlying condition may need to be ruled out.
A doctor can determine whether the bleeding is likely to be from piles, an anal fissure or another gastrointestinal condition and decide whether additional testing is necessary.
Diagnosis begins with a detailed medical history and physical examination.
Your doctor may ask about:
Depending on the findings, investigations may include blood tests, stool tests, colonoscopy or other imaging and endoscopic procedures.
A colonoscopy allows a gastroenterologist to examine the lining of the rectum and colon using a flexible camera.
It can help identify causes of bleeding such as polyps, inflammation, diverticular disease and colorectal cancer. If necessary, tissue samples can be taken or certain polyps can be removed during the procedure.
Not everyone with rectal bleeding requires a colonoscopy. The decision is based on the individual’s symptoms, age, risk factors and clinical assessment.
It depends on the situation.
A small amount of bleeding associated with an obvious episode of constipation may resolve once the underlying problem improves. However, recurring, unexplained or increasing bleeding should not be repeatedly ignored.
Even if the bleeding stops temporarily, the underlying cause may still be present.
This is particularly important when bleeding occurs alongside:
Getting the cause evaluated can provide reassurance when the condition is minor and allow timely treatment when further care is needed.
Some lifestyle measures can help reduce constipation and the risk of problems such as piles and anal fissures.
Include fibre-rich foods such as vegetables, fruits, whole grains, legumes and other high-fibre foods as appropriate for your diet.
Increase fibre gradually if your current intake is low.
Lifestyle measures may help prevent some common causes, but they cannot replace medical evaluation when bleeding is persistent or associated with warning signs.
While haemorrhoids and anal fissures are common causes of blood during bowel movement, rectal bleeding can have several other causes, ranging from infections and inflammatory bowel disease to polyps and colorectal cancer.
The colour and amount of blood can offer clues, but they cannot establish the diagnosis by themselves. If bleeding is recurrent, unexplained, significant or accompanied by changes in bowel habits, weight loss, abdominal pain or other warning signs, consult a gastroenterologist.
Early evaluation can help identify the cause and ensure that appropriate treatment is started when necessary.
Common causes include piles, anal fissures and constipation. Other causes include intestinal infections, inflammatory bowel disease, polyps, diverticular disease and colorectal cancer.
No. Bright red blood can occur with piles and anal fissures, but it may also result from other conditions affecting the lower digestive tract. Recurrent or unexplained bleeding should be evaluated by a doctor.
You should consult a doctor if bleeding is recurrent, increasing, unexplained or associated with abdominal pain, changes in bowel habits, unexplained weight loss, persistent diarrhoea or constipation, or symptoms of anaemia.
Yes. Hard stools and excessive straining can cause small tears in the anal lining or contribute to haemorrhoids, both of which can lead to bleeding during bowel movements.
Yes. Colon cancer symptoms can include blood in or on the stool, changes in bowel habits, unexplained weight loss, abdominal discomfort and iron-deficiency anaemia. However, these symptoms can also occur with many non-cancerous conditions, so proper evaluation is important.
Heavy or continuous bleeding, black tarry stools, dizziness, fainting, severe weakness, severe abdominal pain or vomiting blood can indicate a medical emergency and require immediate medical attention.
Depending on the symptoms and clinical assessment, a doctor may recommend blood tests, stool tests, colonoscopy or other diagnostic investigations. The appropriate test depends on the suspected cause.
