Causes of constipation
  • not eating enough fibre
  • not drinking enough fluid
  • certain medicines, such as antidepressants, calcium or iron supplements or painkillers (eg codeine or morphine)
  • being inactive
  • fear about using the toilet, for example because you worry people can see or hear you
  • stress or depression
  • pregnancy, around four in 10 women who are pregnant have constipation

Constipation can also be a symptom of certain medical conditions, for example:

  • irritable bowel syndrome (IBS)
  • inflammatory bowel disease (Crohn's disease or ulcerative colitis)
  • painful conditions of the anus, such as piles, anal fissure or tears following childbirth
  • conditions affecting the nervous system, such as Parkinson's disease and multiple sclerosis
  • spinal cord injury
  • rectal or colon cancer
  • underactive thyroid

If you are over 40 and develop constipation or notice a change in how often you are having bowel movements, it's very important that you see your doctor.

Symptoms of constipation
  • straining when trying to have a bowel movement
  • feeling as though you haven't fully emptied your bowels
  • having faeces that are small, hard and/or lumpy
  • having fewer than three bowel movements a week
  • pain or discomfort in your abdomen (tummy)

If you have these symptoms or if you notice any other changes in your usual pattern of bowel movement, you should see your doctor.

Diagnosis of constipation

Your doctor will ask about your symptoms and examine you - this may include an examination of your rectum. He or she may also ask about your medical history. Your doctor may refer you for further tests to rule out other medical conditions:

  • Blood tests
  • Sigmoidoscopy. This procedure involves using a narrow, flexible, tube-like telescope (called a sigmoidoscope) to look inside the rectum and lower part of the bowel
  • Colonoscopy. This procedure involves using a narrow, flexible, tube-like telescopic camera (called a colonoscope) to look inside the large bowel
  • Barium enema X-ray. This test involves placing a fluid containing barium (a substance which shows up on X-rays) into the bowel via the rectum. X-ray images of the abdomen then show the inside of the bowel more clearly
Complications of constipation

If constipation isn't treated it can cause complications, including:

  • faecal impaction - this is when hard faeces collects in your rectum and you reach a point where you probably won't be able to have a bowel movement without treatment
  • overflow incontinence - this is when small amounts of loose faeces leak out around the impacted faeces, without you feeling it
  • bleeding from the anus
  • psychological problems, especially in children, such as holding in faeces because passing them has been painful in the past
  • haemorrhoids (piles)
Treatment of constipation

There are several things you can do to help relieve mild symptoms of constipation.


(I) Self-help

It's important that you include plenty of fibre in your diet as this can help to prevent constipation. Insoluble fibre absorbs water and increases the bulk of waste matter in your bowel, which helps to move digested food through your bowel more easily. Only food that comes originally from plants contains insoluble fibre. Good sources include:

  • fruit
  • vegetables
  • wholegrain breakfast cereals
  • wholegrain bread
  • brown rice
  • wheat bran

Soluble fibre, such as oats, beans and pulses can also reduce cholesterol in the blood.


It is recommended that everyone eats five portions of fruit and vegetables a day. This can go a long way towards increasing the amount of fibre in your diet, which will improve symptoms of constipation. It may also help to protect you against other health conditions such as heart disease and some cancers. Sprinkling bran onto your food is another easy way to eat more fibre.


If you don't currently eat much fibre, increase the amount in your diet slowly, otherwise you may get bloating and wind. It's important to continue with a high-fibre diet even if your symptoms don't immediately improve as it may take up to four weeks to have an effect.

You may also need to increase the volume of fluid that you drink, especially if you are increasing the amount of fibre you eat. Speak to your doctor before making any changes to your diet or the amounts that you eat and drink.


Increasing the amount of exercise you do will probably help to ease constipation too.

(II) Medication

If lifestyle changes don't help to relieve constipation, your doctor may suggest a laxative. There are several types of laxative to help relieve constipation. You may need to try more than one type to help improve your symptoms.

  • Bulk-forming laxatives (ispaghula husk, methylcellulose and sterculia). These are recommended if you can't manage to increase the fibre in your diet. You need to drink at least two litres of fluid intake per day if you take these. They contain a type of fibre and work by increasing the amount of content in your bowel. As this builds up, it stimulates your bowel muscles to move and push the faeces out. It may take a few days for bulk-forming laxatives to work.
  • Osmotic laxatives (macrogols or lactulose). These work by increasing the amount of water in your bowel, making faeces softer and easier to pass. These take a few days to work and it's important to drink water if you take these laxatives.
  • Stimulant laxatives (senna or bisacodyl). These work by stimulating the muscles in your bowel to contract more often and with increased force. These work more quickly than other types of laxative. If you take them at night you are likely to have a bowel movement in the morning. Stimulant laxatives can cause abdominal pain.


Generally, you should only use laxatives occasionally. Once your bowel movement pattern returns to usual, you can try to maintain it by eating a balanced diet with enough fluids and fibre.

You can buy laxatives over the counter from a pharmacist without a prescription. However, it's a good idea to see your doctor before trying laxatives because he or she may be able to give you advice on how to relieve your symptoms without needing to use medicines. Always read the patient information leaflet that comes with your medicine and if you have any questions, ask your pharmacist for advice.

Prevention of constipation

You can reduce your risk of constipation by eating a balanced diet with lots of fibre, drinking enough fluids and taking regular exercise.

Last Updated: Aug 2017
Please note that all medical health articles featured on our website have been reviewed by Quality Healthcare doctors. The articles are for general information only and are not medical opinions nor should the contents be used to replace the need for personal consultation with a qualified health professional on the reader’s medical condition.