A small amount of one-off bleeding from your bottom is common and is usually caused by piles or a small tear. But do not self-diagnose. See a GP if it lasts three weeks, ask for an urgent appointment or call NHS 111 if your poo is black, dark red or you have bloody diarrhoea, and call 999 or go to A&E if bleeding is heavy or will not stop. [1]
Noticing blood in the toilet is frightening, and most people immediately fear the worst. This guide explains what the pattern usually means, which signs matter most, and what a doctor will actually do about it.
What the pattern can suggest
Blood from the bottom can show up as blood on the toilet paper, red streaks on your poo, pink water in the bowl, blood mixed into your poo, or very dark poo. NHS guidance gives these common patterns, while being clear you should not diagnose yourself: [1]
Bright red blood on the paper or streaked on the poo, with pain when opening your bowels, often after constipation: commonly a small tear called an anal fissure.
Bright red blood with itching, lumps or discomfort around the bottom: commonly piles (haemorrhoids).
Bright red blood without pain: can be a side effect of blood-thinning medicines such as warfarin, apixaban or aspirin, or fragile blood vessels in the gut.
Blood mixed into the poo, black or dark red poo, or bloody diarrhoea: needs urgent assessment. [1]
When to be seen, and how fast
NHS guidance sets out three levels: [1]
See a GP if you have had blood in your poo for three weeks, your poo has been softer, thinner or longer than normal for three weeks, you are in a lot of pain around the bottom, you have a pain or lump in your tummy, you have been more tired than usual, or you have lost weight without trying.
Ask for an urgent GP appointment or contact NHS 111 if your poo is black or dark red, or you have bloody diarrhoea.
Go to A&E or call 999 if you are bleeding non-stop or there is a lot of blood, for example the toilet water turns red or you see large clots. Do not drive yourself.
There is one reason not to sit on this symptom: bleeding from the bottom is sometimes a sign of bowel cancer, and bowel cancer is far easier to treat when it is found early. Getting checked is how you find out it is something simple. [1]
What a doctor will do
A GP assessing rectal bleeding may examine your bottom with a gloved finger, ask for a poo sample for testing, and refer you for further tests if needed. For many people the consultation ends with a clear, benign explanation and a plan. For some, it starts an investigation that is much better started early. Either way, the uncertainty ends. [1]
What to have ready
How long you have noticed blood and what it looks like: bright red, mixed in, or black.
Any change in your bowel habit, and how long that has been going on.
Pain, itching or lumps around the bottom.
Your medicines, especially blood thinners and regular aspirin.
Any tiredness, weight loss or tummy pain, and your family history of bowel conditions.
How The Online GP can help
If you want a prompt medical view, a telephone consultation is £59 for up to 15 minutes, and video consultations are from £150 for up to 30 minutes, usually the same day. Your doctor can assess the pattern, arrange stool tests or a referral, and examine you in person where needed. If your symptoms meet the urgent criteria above, use NHS 111 or 999 first rather than waiting for any private appointment. [1,2]
For a wider look at bowel health, read our guide to bowel and gut health screening and piles treatment in London. [3,4]
Common questions
Bright red blood once, then nothing. Do I still need a doctor?
A single small bleed often settles on its own. If it keeps happening, lasts three weeks, or comes with a change in your bowels, tiredness or weight loss, get checked. [1]
Does blood in poo always mean cancer?
No. Piles and small tears cause most rectal bleeding. Cancer is the reason doctors take the symptom seriously, not the usual explanation. [1]
Can I be assessed by video?
A doctor can take the full history, review photographs where appropriate, order stool tests and arrange referral remotely. A physical examination, if needed, happens in person. [2]
I take blood thinners and noticed blood. What should I do?
Do not stop your medicine on your own. Contact a doctor the same day to assess the bleeding and advise on your treatment. [1]
Get checked, do not guess
Book a consultation, call 020 3951 3429, or email team@thewellnesslondon.com. Urgent symptoms go to NHS 111 or 999 first.
Sources
The Wellness Clinical Team. Sources checked 17 October 2026. General information, not an individual diagnosis or treatment plan.