Go to A&E or call 999 if you're bleeding non-stop, or if there's a lot of blood, for example the toilet water turns red, or you see large blood clots.
Ask for an urgent GP appointment, or contact NHS 111, if your poo is black or dark red, or you have bloody diarrhoea.
Seeing blood is frightening, and the instinct to wait a few days is very human. Blood in your poo is often caused by piles, especially when it's bright red and fresh, but there are several possible causes.
This is one of the few symptoms where the difference between going now and going in six months genuinely changes the outcome. So this page leads with what to do, and explains afterwards.
What the NHS Recommends
See a GP if: 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, or you've lost weight for no reason [1]. A small amount of one-off bleeding is not usually a serious problem, according to the NHS, but a GP can check. Getting told it's piles takes ten minutes. Not getting told anything takes considerably longer to undo.
Where the Blood Appears Can Sometimes Suggest Something
Blood colour and whether it's mixed with stool can give clinicians clues, but appearance alone can't reliably tell you where bleeding is coming from, only a GP can properly assess that.
| What you see | What it can sometimes suggest |
|---|---|
| Bright red, on paper or in the bowl, not mixed in | Bleeding near the anus, such as piles or a fissure |
| Blood mixed into the stool | Bleeding from further inside the bowel |
| Black, tarry stool with a strong offensive smell | Can indicate bleeding higher up. See our guide to black stool, get same-day help |
| Bright red after beetroot or red food colouring | Food pigment can sometimes cause the colour |
What Causes It
Cancer Research UK puts it plainly: blood in your poo can be a sign of bowel cancer, but it is often due to other causes, most often piles, especially when it's bright red, fresh blood [2]. Haemorrhoids are swollen blood vessels causing bright red blood, often with itching or discomfort, and are frequently linked to straining and constipation. An anal fissure is a small tear, usually from passing something hard, distinctive because of a sharp, tearing pain. Inflammatory bowel disease, such as Crohn's or ulcerative colitis, can cause blood mixed with mucus alongside diarrhoea and fatigue, a picture explored further in how IBS and related conditions affect daily life. Diverticular disease and bowel polyps can also bleed, the latter often with no other symptoms, which is why removing certain polyps can reduce cancer risk. Bowel cancer is not the most likely cause, but it's the reason not to wait and see.
Why Early Assessment Matters
Bowel cancer is generally easier to treat when found early. These are Cancer Research UK's five-year net survival estimates for people diagnosed in England between 2016 and 2020, by stage:
These are population statistics and cannot predict an individual's outcome. That is the argument for a ten-minute appointment you will probably be told was nothing.
NHS Bowel Cancer Screening
Screening is for people without symptoms, if you're bleeding, see a GP instead. England, Scotland and Wales screen ages 50 to 74 every 2 years, Northern Ireland 60 to 74 every 2 years, and it's a home test you post back [4][5][6].
What to Tell Your GP
When you first noticed it and how often since, whether it's on the paper, in the water, or mixed in, the colour, any pain, whether your bowel habit has changed, any weight loss or tiredness, family history, and your medications, particularly blood thinners. You don't need all of this. A simple line like noticing it twice last week, bright red on the paper, is a perfectly good start.
I'm young. Do I still need to get it checked?
Yes. Bowel cancer is more common with age, but blood in your poo can have many causes at any age. If you're concerned, speak to a GP.
I've had piles for years. Can I assume it's that?
Having piles does not protect you from anything else, and it's a common reason bleeding gets dismissed for months. A change in a pattern you thought you understood is worth a look.
Blood in your poo is often piles, but don't assume that automatically. Non-stop bleeding or a lot of blood means A&E or 999. Black or dark red poo, or bloody diarrhoea, means an urgent GP or 111. Bleeding for three weeks, a change in bowel habit, pain, a lump, tiredness or weight loss means see a GP. For more, see our stool colour chart and Bowel Cancer Awareness Month.
References
- NHS. Bleeding from the bottom (rectal bleeding). NHS.uk.
- Cancer Research UK. Bowel cancer symptoms. cancerresearchuk.org.
- Cancer Research UK. Bowel cancer survival. cancerresearchuk.org.
- NHS. Bowel cancer screening. NHS.uk.
- GOV.UK. Bowel cancer screening programme overview. gov.uk.
- nidirect. Bowel cancer screening (Northern Ireland). nidirect.gov.uk.
This content is for informational purposes only and does not constitute medical advice. If you have noticed blood in your poo, please speak to a qualified healthcare professional.
