Alarm Signals

Constipation is usually just a nuisance. There is no scientific evidence that ‘toxins’ from poo in the bowel can affect your health. However, very occasionally it is a sign of serious disease such as cancer of the colon (large bowel). So it is very important that you see your doctor if any of the following applies to your symptoms. (If this is difficult for you, have a look at our section on seeing your doctor about an anal problem.)

  • Your constipation is a new symptom, and there is no obvious reason for it.
  • It is severe and changing your diet hasn’t helped.
  • The constipation alternates with diarrhoea.
  • You have noticed other symptoms, such as bleeding from the back passage (even if you think this is caused by piles), passing slime from the back passage, tummy pain, weight loss, and/or pain in the back passage when you strain to have a poo.
  • Anyone in your family has had colon cancer at a young age (generally less than 50 years old).

Rectocoele (Rectal Prolapse)

Sometimes, on straining, in women poo can bulge from the rectum into the vagina and become trapped in what is known as a rectocoele. This is not dangerous and can be treated. Sometimes the rectocoele can be helped to empty by placing a finger into the vagina or sometimes by supporting the pelvic floor muscles whilst straining. Often, a weakness in the supporting pelvic floor can be treated quite successfully using bowel retraining exercises and very specific use of certain laxatives. This is best done in consultation with your family doctor. (In men, rectocoele is uncommon, and the protrusion of the rectum is usually backwards rather than forwards.)

Underactive Thyroid

This is an often overlooked cause of constipation, so see your doctor if you are also chronically tired, over-sensitive to cold or gaining weight, or if your hair is thinning.

Painful Conditions

If you have a painful anal condition, look at our sections on anal pain, piles (haemorrhoids) and anal fissure. If having a poo is painful you should see your doctor. If you are worried about discussing the problem, have a look at our section on seeing your doctor about an anal problem.


Medications that commonly cause constipation are discussed here. Obviously, you should not stop a medicine that has been prescribed for you just because it is making you constipated – it could be an important medication for you – so discuss it with your family doctor.

Shy Bowel

The term ‘shy bowel’ has been used to describe difficulty in using the lavatory when other people are around. This condition can be quite problematic, and you should discuss it with your doctor, as certain psychological treatments (such as cognitive behavioural therapy) can help.


First published on:
Reviewed and edited by: Dr Kevin Barrett
Last updated: October 2020

Related Posts

Gastroesophageal reflux disease affects 10–30% of the Western population. Patients may dismiss it as “permanent indigestion” and try to cope...
Clostridioides difficile (C. difficile) is a bacteria that can lead to mild and serious bowel problems. The authors of the...
Helicobacter pylori (H. pylori) is a type of bacteria that can cause infection in the stomach. It is known to...


Share your opinion with us and leave a comment below!