What is blood in stool (poo)?

You might see blood in your stool (poo), after using the toilet. You may also see spots of blood on the toilet paper or drops of blood in the toilet bowl.

A small amount of bleeding one time is usually not serious. But blood in your stool can indicate a range of problems, some of which are very serious. So, it's best to get a doctor to check.

What symptoms are related to blood in stools?

Blood in your stool can be bright red, dark red or black. The colour of the blood depends on where the blood is coming from.

Spots of red blood indicate the bleeding is coming from your large intestine or rectum.

If the blood is dark red and mixed in with your poo it may be from higher up in your bowel, such as your colon or small intestine.

If your stools are black like tar, and smell bad, the blood is probably coming from higher up in your gastrointestinal tract.

What causes blood in stools?

Blood in your stool can be caused by many different things. These can include:

• anal fissures, which are small painful cracks in the anus
• haemorrhoids
• gastroenteritis (tummy bug)
• diverticular disease
• inflammatory bowel disease — Crohn's disease or ulcerative colitis
• polyps — an early sign of bowel cancer

Sometimes poo can look like it's mixed with blood after you've eaten a lot of red or purple foods. Foods like tomatoes and beetroot can cause this to happen.

Very dark or black blood or poo can be caused by:

• bleeding in your stomach
• stomach ulcer
• side effects of medicines such as warfarin

Sometimes your poo can look very dark or black if you:

• take iron tablets
• eat a lot of dark foods like liquorice and blueberries

How is the cause of blood in stools diagnosed?

Your doctor will talk with you about your symptoms. They will also examine you and may arrange some tests to investigate the cause.

Your doctor will choose the right test for you based on your age, symptoms and medical history. Possible tests include:

• rectal examination — your doctor checks your bottom with a gloved finger
• blood tests
• stool (poo) tests

Your doctor may also refer you to a specialist for further tests, such as a:

• sigmoidoscopy — a flexible tube with a camera on the end is used to check inside your rectum and your lower large intestine ('sigmoid colon')
• colonoscopy — a flexible tube with a camera on the end is used to examine your entire colon
• gastroscopy — an endoscope (flexible tube with a camera on the end) is used to look at your oesophagus (food pipe), stomach and first part of your small intestine

Some of these tests are done under sedation. You may need to go to hospital. Ask your doctor for more information.

When should I see a doctor?

Ask for an urgent doctor's appointment if:

• your poo is dark red or black
• you have bloody diarrhoea

If you have blood in your poo for 3 weeks, make sure you get it checked out by a doctor.

You should also see your doctor if you:

• have a change in how often you poo or the texture of your poo
• have abdominal pain
• feel very tired or weak

Blood in your stool is sometimes a sign of bowel cancer. This is easier to treat if it's found early.

Always see your doctor if you have blood in your stools, even if you've had a known cause in the past.

When to seek urgent care

Go to the emergency department if you are:

• bleeding non-stop
• there's a lot of blood — the toilet water is red and there are large blood clots

How is blood in stools treated?

It's important to find the cause of the blood in your stools because that will determine the treatment you need.

Self-care at home

Some causes of bleeding such as haemorrhoids or anal fissure may be treated by changes to your lifestyle or diet.

Medicines for blood in stools

It's also a good idea to have your doctor or pharmacist review your medicines if you have blood in your stools or dark stools.

Always see your doctor if you have blood in your stools, even if you've had a known cause in the past.

Can blood in stools be prevented?

There are some things you can do to help prevent some causes of blood in your stool.

It's a good idea to:

• drink plenty of water
• eat a healthy and varied diet
• keep active
• go to the toilet when you need to and avoid straining

It's important to have screening tests for bowel cancer. Bowel cancer screening tests are sent to all Australians aged between 50 and 74 years. This happens as part of the National Bowel Cancer Screening Program.

Resources and support

You can call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with 24 hours a day, 7 days a week.