Bisacodyl is a laxative. This type of medicine can help you empty your bowels if you have constipation (difficulty pooing).

Bisacodyl is also used in hospitals to help you empty your bowels before surgery or some examinations or treatments. Your hospital will explain how to use it.

Bisacodyl comes as a tablet and a suppository (a medicine that you push gently into your anus).

The tablets and suppositories are available on prescription. Small packs are available to buy from supermarkets (up to 20 tablets).

Before trying bisacodyl, it's better to try other ways to help your constipation by:

• having more fibre in your diet and drinking more water
• exercising

Only use bisacodyl if you have tried other types of laxatives first such as:

• bulk-forming laxatives like Fybogel (ispaghula husk) and methylcellulose
• osmotic laxatives like lactulose and polyethylene glycol

• Bisacodyl is known as a stimulant laxative. It relieves constipation by helping your bowel move so you can poo more easily. It also softens your poo.
• Bisacodyl tablets take 6 to 12 hours to work. The suppositories take 10 to 45 minutes to work, so it's best to stay close to a toilet after you've used them.
• The most common side effects are feeling sick (nausea), diarrhoea, stomach pain or cramps.
• Only give bisacodyl to children and young people if a doctor or pharmacist recommends it.
• Do not take bisacodyl tablets or use bisacodyl suppositories every day for more than 5 days.

Bisacodyl can be used by most adults aged 18 years and over.

Young people aged 12 to 17 years can take bisacodyl tablets and use suppositories if a doctor or pharmacist says it's OK.

Children aged 11 years and under can only take and use bisacodyl if a doctor prescribes it.

Always follow the advice of a pharmacist or doctor, and the instructions that come with your medicine.

Dosage for tablets

Bisacodyl tablets you buy (self-treatment)

The usual dose for adults and young people aged 12 years and over is 5mg to 10mg, taken once a day at bedtime.

If you have not taken bisacodyl before, start with one 5mg tablet and if that does not work you can increase the dose to a maximum of two 5mg tablets (10mg) at bedtime.

Like all medicines, bisacodyl may cause side effects in some people, but many people have no side effects or only minor ones.

Common side effects

Common side effects, which happen in more than 1 in 100 people, are:

• feeling sick (nausea)
• diarrhoea
• stomach pain or cramps

These side effects are mild and usually go away after a couple of days. Talk to your doctor or pharmacist if the side effects bother you or do not go away.

Serious side effects

Call your doctor straight away if these rare side effects happen to you:

• feeling dizzy
• blood in your poo
• being sick (vomiting)

Serious allergic reaction

In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to bisacodyl.

What to do about:

• feeling sick – try taking bisacodyl with some food. It may also help if you avoid rich or spicy food.
• diarrhoea – stop taking bisacodyl and drink plenty of water or other fluids. Speak to a pharmacist if you have signs of dehydration, such as peeing less than usual or having dark, strong-smelling pee. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor.
• stomach pain or cramps – reduce your dose of bisacodyl or stop taking it until these side effects go away.

Bisacodyl tablets or suppositories are not generally recommended if you are pregnant. Talk to your doctor about whether taking bisacodyl is right for you.

If you are pregnant, it's better to try to treat constipation first without taking a medicine. Your doctor or midwife will advise you to eat more fibre and drink plenty of fluids. It may also help to increase your level of exercise if you can.

If diet and lifestyle changes do not work, your doctor or midwife may recommend other laxatives, such as lactulose or Fybogel. These are more suitable to take during pregnancy and while breastfeeding.

Bisacodyl and breastfeeding

If your doctor or midwife recommends bisacodyl, rather than lactulose or Fybogel, it's OK to use it while you're breastfeeding. It does not seem to pass into breast milk and is very unlikely to affect your baby.

As with any medicine, if you notice that your baby is not feeding as well as usual, or if you have any other concerns about your baby, talk to your health visitor, midwife or doctor as soon as possible.

Some medicines, and some foods, affect the way bisacodyl works.

They include:

• medicines that make you pee more (diuretics), steroids (like prednisolone) or digoxin (a heart medicine) – these can upset the balance of salts and minerals in your body if you have too much bisacodyl. If you are taking digoxin, this imbalance makes it more likely you will have the serious side effects of digoxin. Talk to a doctor or pharmacist before taking bisacodyl if you are taking any of these medicines.
• indigestion remedies (antacids) – these stop bisacodyl tablets working properly. They can also make the bisacodyl irritate your stomach and give you indigestion. Do not take bisacodyl at the same time. Leave a gap of 1 hour before or after taking bisacodyl if you are having indigestion remedies.

Mixing bisacodyl with herbal remedies or supplements

There is not enough research to know if complementary medicines and herbal remedies are safe to take with bisacodyl. They are not tested in the same way as other medicines.