Bisacodyl (Dulcolax)

Bisacodyl should only be used to provide short-term relief from constipation.

If you are still constipated after using bisacodyl for five days, you should see your doctor.

Eating a healthy diet, drinking plenty of water and getting regular gentle exercise can all help maintain good bowel function.

Type of medicine Stimulant laxative
Used for Constipation
Before some surgery and medical examinations
Also known as Dulcolax®
Available as Tablets and suppositories

Constipation can be caused by a poor diet, not drinking enough water and not going to the toilet as soon as you feel you need to. Pregnancy, a lack of exercise or movement (such as being ill in bed) and some medicines, including some painkillers, can also cause constipation.

However, many people take laxatives when they do not need to because they believe that they are constipated unless they go to the toilet every day. This is not the case. A useful definition of constipation is going to the toilet less frequently than is normal for you, and passing hard stools (poo) when you do go.

Bisacodyl works by encouraging the muscles in your bowel to move stools through your body. This helps you to go to the toilet. Tablets usually have an effect within 10-12 hours, and suppositories usually within 20-60 minutes. Bisacodyl preparations are available to buy without a prescription at pharmacies and other retail outlets.

Bisacodyl is sometimes used to clear the bowel before a medical examination which requires the bowel to be empty. When it is used like this, you will be provided with a small supply of bisacodyl by your hospital or clinic.

To make sure this is the right treatment for you, ask for advice from a doctor or pharmacist before you start using bisacodyl if any of the following apply to you:

  • If you are pregnant, trying for a baby or breast-feeding. This is because, while you are expecting or feeding a baby, you should only take medicines on the recommendation of a doctor.
  • If it is for a child under 10 years of age. This is because bisacodyl should only be given to children on the advice of a doctor or healthcare professional.
  • If you have severe pain in your abdomen and feel sick.
  • If you have recently had any bowel or abdominal surgery.
  • If you are dehydrated or take diuretics ('water tablets').
  • If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
  • If you have ever had an allergic reaction to a medicine.
  • Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The leaflet will give you more information about bisacodyl and a full list of side-effects which you may experience from taking it.
  • Take one or two 5 mg tablets with a drink of water (do not take with milk). Bisacodyl tablets take about 10-12 hours to work; therefore, they are best taken at bedtime. Do not chew or break the tablets.
  • A suppository can be used instead of taking tablets. Use one suppository daily. It will take about 20-60 minutes to work and therefore should preferably be used in the morning. There are two strengths of suppository: 10 mg which is suitable for adults, and 5 mg which is suitable for older children (and younger children when prescribed by a doctor).
  • Bisacodyl should only be used for a short time. This is because your bowel can start to rely on this type of laxative to make it work rather than working on its own. If you are still constipated after taking bisacodyl for five days, you should speak with your doctor.

How to use a suppository

  1. Remove the suppository from the wrapping.
  2. Moisten the suppository with a little tap water.
  3. Using your finger, gently push the suppository into the rectum (back passage) as far as possible, pointed end first.
  4. Remain still for a little while to help hold the suppository in place. It will start to work in about 20 minutes or so.
  5. Wash your hands after use.
  • Do not take indigestion remedies at the same time as bisacodyl tablets. This is because bisacodyl tablets have a special coating on them which is affected by antacid preparations. If you need to take something for indigestion, make sure you take it more than two hours before you take bisacodyl, or alternatively wait for two hours after you have taken bisacodyl.
  • A healthy diet containing fibre (whole grain breads and cereals, bran, fruit and green leafy vegetables) with 6 to 8 full glasses of water each day and daily exercise are important in maintaining healthy bowel function. For people who have problems with constipation, food such as pastries, puddings, sugar, sweets, cheese and cake can make matters worse.
  • You can read more about how to prevent or treat constipation in the separate leaflets called Constipation in Adults and Constipation in Children.

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. These usually improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.

Common bisacodyl side-effects - these affect less than 1 in 10 people who use this medicine What can I do if I experience this?
Feeling sick Stick to simple foods
Diarrhoea Stop using bisacodyl. This can be a result of taking bisacodyl unnecessarily or for too long
Cramps, discomfort This should soon pass
Suppositories may cause irritation to the bottom Try applying a gentle moisturiser

If you experience any other symptoms which you think may be due to this medicine, speak with your doctor or pharmacist.

  • Keep all medicines out of the reach and sight of children.
  • Store in a cool, dry place, away from direct heat and light.

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital at once. Take the container with you, even if it is empty.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you are having an operation or dental treatment, tell the person carrying out the treatment which medicines you are taking.

If you buy any medicines, check with a pharmacist that they are suitable for you to take with your other medicines.

If you have any questions about this medicine ask your pharmacist.

Further reading & references

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.

Original Author:
Helen Allen
Current Version:
Peer Reviewer:
Dr Helen Huins
Document ID:
3226 (v24)
Last Checked:
22/04/2013
Next Review:
21/04/2016
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