If you have blood in your stools and you feel faint, dizzy or light-headed, this may be an emergency. Go to the nearest emergency department as soon as possible or call triple zero (000) and ask for an ambulance.

Go to the emergency department if you have heavy rectal bleeding and also have bad stomach pains.

Appearance of blood in stools

How the blood looks depends on where it is coming from.

Spots of red blood on the toilet paper, drops in the toilet bowl or blood on the surface of your stool indicate a problem in the anus and lower rectum.

However, if the blood is mixed in with your stool, this suggests bleeding might be from higher up in the bowel.

If your stools are black and like tar, and they smell bad, this is also probably because the blood is coming from higher up in the bowel.

Causes of blood in stools

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

• haemorrhoids
• anal fissures, which are small painful cracks in the anus
• bowel infections
• bowel cancer
• colorectal polyps, which are small growths that can become cancerous
• inflammatory bowel disease (Crohn's disease and ulcerative colitis)
• diverticular disease
• an injury

When to see a doctor

If you have any blood in your stool, make sure you get it checked out by a doctor.

As well as blood in your stool, you might have other symptoms that could indicate something more serious is going on.

If you have blood in your stools and you feel faint, dizzy or light-headed, this may be an emergency. Go to the nearest emergency department as soon as possible or call triple zero (000) and ask for an ambulance.

If you are losing weight and have blood in your stools, this suggests an illness that needs treatment. See your doctor as soon as possible.

If you received some trauma to the area, you might have an injury or a foreign object in the area. Seek an examination from your doctor as soon as possible.

Tests for blood in stools

Your doctor will talk to you, examine you, and should arrange some tests to investigate the cause. The doctor will choose the right test for you based on your age, symptoms and medical history. Possible tests include:

• rectal examination — your doctor or nurse looks and feels around your rectum, anal canal and nearby organs, such as the prostate and bladder
• anoscopy — a procedure where your doctor will use a camera in a tube to view the last 5cm of your anus and lower rectum
• sigmoidoscopy — a procedure where your doctor uses a camera to check inside your rectum and most of your lower large intestine (‘sigmoid colon’)
• colonoscopy — a physician uses a camera that sits within a tube to examine your entire colon

Some of these tests are done under sedation and anaesthetic. Ask your doctor for more information.

Treatment

If you notice any blood in your stool, see your doctor for an examination as soon as possible. 

The right treatment for blood in your stool depends on what is causing the problem.

For some problems, the treatment could be to make changes to your lifestyle or diet.

If the blood in your stool is caused by something more serious, such as diverticular disease or bowel cancer, you might need more urgent and invasive treatment.