Blood in Stool

What Does Blood In Your Stool Mean?

Blood in your stool means bleeding somewhere along the digestive tract, and how it looks is a clue to where it has come from. According to the NHS, you might be bleeding from the bottom if you have blood on your toilet paper, red streaks on the outside of your poo, pink water in the toilet bowl, blood in your poo or bloody diarrhoea, or very dark poo, which can be blood mixed in [1].

Bright red blood usually comes from close to the back passage. Blood mixed through the stool tends to come from higher up. A very dark or black stool can mean bleeding in the stomach or upper gut. Not every colour change is blood at all - the NHS notes that poo can look mixed with blood after a lot of red or purple foods like tomatoes and beetroot, and can look very dark if you take iron tablets or eat plenty of liquorice or blueberries [1].

When Should You Seek Assessment For Blood In Your Stool?

Use the NHS guidance below as a general guide to urgency, not as a diagnosis. A small amount of one-off bleeding can often go away on its own without needing treatment [1].

See a GP if [1]:

• your child has blood in their poo
• you've had blood in your poo for 3 weeks
• your poo has been softer, thinner or longer than normal for 3 weeks
• you're in a lot of pain around the bottom
• you have a pain or lump in your tummy
• you've been more tired than usual
• you've lost weight for no reason

Ask for an urgent GP appointment or get help from NHS 111 if [1]:

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

You can call 111 or get help from 111 online [1].

Go to A&E or call 999 if [1]:

• you're bleeding non-stop
• there's a lot of blood - for example, the toilet water turns red or you see large blood clots

Do not drive to A&E. Ask someone to drive you or call 999 and ask for an ambulance. Bring any medicines you take with you [1].

LivingCare is a specialist outpatient service and is not an emergency care facility. If your symptoms are sudden or severe, call 999.

Where the bleeding is not an emergency but has not settled, you can book a Gastroenterology Consultation privately rather than wait. As the NHS puts it, bleeding from the bottom is sometimes a sign of bowel cancer, and this is easier to treat if it's found early, so it's important to get it checked [1].

What Might Be Causing Blood In My Stool?

There are several common explanations, and most of them are not serious. The NHS groups them by how the bleeding looks [1].

• Bright red blood on the paper, streaked on your poo or colouring the toilet water is most often piles (haemorrhoids) or a small tear in the anus (anal fissure), particularly if pooing is painful. It can also follow a sexually transmitted infection, or be a side effect of medicines that help prevent blood clots, such as warfarin, apixaban, clopidogrel or aspirin.
• Blood in your poo, or blood with slime, can point to a tummy bug (gastroenteritis), an anal fistula, an inflammatory bowel disease such as ulcerative colitis or Crohn's disease, or bowel polyps and early signs of bowel cancer.
• Very dark or black poo can mean bleeding in the stomach or gut - from a stomach ulcer, an injury, or the same blood-thinning medicines.

The NHS is clear that these are pointers, not answers: do not self-diagnose, and see a GP if you're worried [1]. Blood alongside a change in your bowel habit or unexplained weight loss is worth raising, and both of those symptoms have their own pages - Changes in Bowel Habit and Unexplained Weight Loss. For a fuller, cause-by-cause look at each of the explanations above, read Blood In Your Poo: What Does It Mean - And What Should I Do About It?.

How Blood In The Stool Is Assessed

A visit to your GP or gastroenterology consultation is the starting point - the specialist reviews your symptoms and arranges only the tests they call for.

At a GP appointment for rectal bleeding, the NHS says they might check your bottom (rectum) with a gloved finger, ask for a sample of poo for testing, or refer you to a specialist for tests [1]. A private assessment follows the same logic. Depending on your symptoms, that can mean a stool test such as the qFIT Home Test, which checks for traces of blood you cannot see, blood tests, or a Colonoscopy to examine the large bowel.

NICE guidance sets out when a stool test should lead on to a specialist referral. It recommends offering a quantitative faecal immunochemical test (FIT) to guide referral for suspected colorectal cancer in adults aged under 50 who have rectal bleeding with unexplained abdominal pain or weight loss, and in adults aged 50 and over with unexplained rectal bleeding, abdominal pain or weight loss. A FIT result of at least 10 micrograms of haemoglobin per gram of faeces prompts a suspected cancer pathway referral, which NICE defines as the person receiving a diagnosis or ruling out of cancer within 28 days [3].

A FIT test is usually arranged by most GP practices.

Self-pay, with no GP referral needed. If you are using medical insurance, your insurer may ask for a GP referral letter. You can book a Gastroenterology Consultation or read more about our Gastroenterology service.

References

1. NHS - Bleeding from the bottom (rectal bleeding). Page last reviewed 12 April 2023: https://www.nhs.uk/conditions/bleeding-from-the-bottom-rectal-bleeding/
2. Cancer Research UK - Bowel cancer survival. Five-year net survival, NHS England data for people diagnosed between 2016 and 2020 with follow-up to 2021: https://www.cancerresearchuk.org/about-cancer/bowel-cancer/survival
3. NICE - Suspected cancer: recognition and referral (NG12), published 23 June 2015, last updated 12 January 2026: https://www.nice.org.uk/guidance/ng12
4. NHS - Bowel cancer screening. Page last reviewed 11 October 2024: https://www.nhs.uk/conditions/bowel-cancer-screening/
5. NHS - Symptoms of bowel cancer. Page last reviewed 9 March 2023: https://www.nhs.uk/conditions/bowel-cancer/symptoms/

Medically reviewed by: Dr N. Chandra, Consultant Endoscopist. Last reviewed: 09/10/26