Diagnosing constipation 

Constipation is a very common condition. Your GP won't usually need to carry out any tests or procedures, but will confirm a diagnosis based on your symptoms and medical history.

Your GP will ask you some questions about your bowel habits. Don't feel embarrassed about discussing this with your GP. It's important they're aware of all of your symptoms, so they can make the correct diagnosis.

Your GP may also ask questions about your diet, level of exercise and whether there have been any recent changes to your routines.

Doctors define constipation in a number of ways:

  • opening the bowels less than three times a week
  • needing to strain to open your bowels on more than a quarter of occasions
  • passing a hard or pellet-like stool on more than a quarter of occasions

Physical examination

If your GP thinks you may have faecal impaction (when dry, hard stools collect in your rectum), they may carry out a physical examination. See complications of constipation for more information about faecal impaction.

A typical examination will begin with you lying on your back, while the GP feels your abdomen (tummy). You'll then lie on your side while your GP carries out a rectal examination using a lubricated, gloved finger. Your GP will be able to feel for any stools that may have collected.

An internal physical examination rarely needs to be carried out on a child. Instead, the diagnosis can usually be made by feeling the child's tummy.

Further tests

If you're experiencing severe symptoms, your doctor may request further tests, such as blood tests or thyroid tests, to diagnose or rule out other conditions.

Other tests you may have include:

  • an abdominal X-ray – where X-ray radiation is used to produce images of the inside of your abdomen
  • transit study examination – where you take a short course of special capsules that show up on X-rays; one or more X-rays are taken later on to see how long it takes for the capsules to pass through your digestive system
  • anorectal manometry – where a small device with a balloon at one end is inserted into your rectum and attached to a machine that measures pressure readings from the balloon as you squeeze, relax and push your rectum muscles; this gives an idea of how well the muscles and nerves in and around your rectum are working

As there's an increased risk of bowel cancer in older adults, your doctor may also request tests to rule out a diagnosis of cancer, including a computerised tomography (CT) scan or colonoscopy.


Page last reviewed: 24/12/2015

Next review due: 24/12/2017