It’s not a topic we like to talk about, but rectal bleeding is a common experience. In most cases, there’s a benign cause: usually haemorrhoids or piles, which are easily treated. But in some instances, rectal bleeding can be a sign of something more serious.
In this article, colorectal surgeon Professor Richard Cohen talks through different kinds of rectal bleeding, common causes, diagnosis and treatment.
Are there different types of rectal bleeding?
Yes. Rectal bleeding can vary by amount, colour and frequency.
Signs of rectal bleeding include:
- blood in your stool or bloody diarrhoea
- pink/red-tinged water in the toilet bowl
- red streaks around your stool
- blood on your toilet paper
- dark, bad-smelling stool
Is there a difference between bright red and dark red blood?
The assumption is that bright red blood probably originates from within or close to the anal canal, whereas dark blood comes from further up the colon (becoming dark as it gets processed around the colon).
As such, if your stool is black or dark red it is a good idea to get medical advice, as the cause of your bleeding is more likely to be serious than bright red bleeding (which is usually linked to haemorrhoids or fissures – more on this below).
Do not forget that foods and medication can colour your faeces: iron medication gives a greeny black colour and beetroot can make a reddish colour.
Common causes of rectal bleeding
The most common causes of rectal bleeding are very benign disorders of the anal canal, such as haemorrhoids (piles) or a fissure (a tear).
Haemorrhoids are vascular cushions of tissue in the anal canal, that can be internal or external. There are lots of theories as to the causes of haemorrhoids, including: heavy lifting, sitting on the toilet for a long time or constipation. You are also more likely to develop a haemorrhoid if you are pregnant due to pressure from the foetus on the pelvic veins, or if you have a diet low in fibre.
Fissures are sometimes confused with haemorrhoids. They are a tear or ulcer in the skin that lines the anus, and can happen when you pass a particularly hard stool. Fissures often go away on their own and as long as they are not too painful or troublesome, you should not worry too much about them.
Bleeding could less commonly be a sign of inflammatory bowel disease (IBD), diverticulitis, an anal abcess or fistula or polyps.
Though rectal bleeding is usually a sign of a minor condition, you should always see your doctor if you’re worried, as the bleeding could be a sign of something more serious. Large polyps, for instance, can become cancerous with the passage of time and are very amenable to removal at colonoscopy.
When should I see a doctor about rectal bleeding?
You should never be too embarrassed to seek medical reassurance if you have rectal bleeding, particularly if it is persistent, dark coloured, associated with a change in your bowel habits and/or abdominal pain.
If you only experience one-off bleeding and it’s a small amount, you probably don’t need to see a doctor.
If you’re bleeding a lot and see large blood clots in the toilet bowl, you should seek urgent medical advice.
If you have a family history of bowel cancer or colitis, you should particularly take rectal bleeding seriously.
Diagnosis of the cause of rectal bleeding
We diagnose the cause of your rectal bleeding by carefully listening to your symptoms and medical history, followed by a gentle physical examination, often using a small device (proctoscope) to look inside the anal canal.
We also use a FIT test to look for blood in your stool, which gives an indication as to whether further investigation is required.
Treatment for rectal bleeding
If you’re diagnosed with a condition such as haemorrhoids or fissures, these can be easily treated. Some treatments for haemorrhoids include:
- Change to diet – eating lots of high-fibre foods
- Haemorrhoid cream
- A warm bath, 10-15 minutes a day
- Over-the-counter pain medications, such as aspirin or paracetamol
The above treatments equally apply to fissures. As well as haemorrhoid cream, over-the-counter stool softeners and topical pain creams can help with fissures specifically. Fissures often go away on their own, but if not, your doctor may recommend a surgical procedure called an anal sphincterotomy.
In some cases, you may need surgery to remove a haemorrhoid, such as an haemorrhoidectomy or minimally invasive procedure, like rubber band ligation or the Rafaelo procedure.
If there is a possibility that the cause of your bleeding isn’t a haemorrhoid or fissure and further investigation is needed, you may need a colonoscopy or flexible sigmoidoscopy. We now offer virtual colonoscopy, which is done with a CT scanner and can be less invasive than colonoscopy.
All treatment will be tailored to your wishes and individual circumstances.