How does bisacodyl work?
Bisacodyl is a type of laxative called a stimulant laxative. It relieves constipation by helping your bowel move and also softening your poo so you can poo more easily.
When will I feel better?
Bisacodyl tablets usually work within 6 to 12 hours after taking them.
The suppositories can take 10 to 45 minutes, so it's best to stay close to a toilet.
Are there any long-term side effects?
You should only use bisacodyl occasionally and for a few days at a time.
Using laxatives like bisacodyl for longer than this can lead to diarrhoea.
It can also cause an electrolyte (or salt) imbalance, where levels of sodium, potassium and magnesium in your body get too high or too low. A severe electrolyte imbalance can cause serious health problems such as:
- muscle spasms
- twitching
- a seizure or fit
Using bisacodyl for many weeks, even months, could also stop your bowel working properly on its own.
If you need to use laxatives every day for longer than 5 days, talk to your doctor.
Will I gain or lose weight?
Bisacodyl does not help with weight loss. It does not reduce calories taken in by your body.
How does bisacodyl compare with other laxatives?
There are several types of laxatives. They work in a different way from bisacodyl but are equally good at treating constipation.
Bulk-forming laxatives, such as Fybogel, increase the "bulk" or weight of poo, which in turn stimulates bowel movement. They take 2 or 3 days to work.
Osmotic laxatives, such as lactulose, draw water from the rest of the body into your bowel to soften your poo and make it easier for you to go to the toilet. They take at least 2 days to work.
Stimulant laxatives, like senna, stimulate the muscles that line your gut, helping them to move poo along your gut to your anus (bottom). Senna takes about 8 hours to work.
Can I use bisacodyl after surgery?
It's quite common to have constipation after surgery. Using a laxative may help.
If you have constipation after an operation, it's better to use lactulose because it is gentler on your stomach muscles than bisacodyl. You can get lactulose on prescription or buy it from pharmacies.
Will it affect my contraception?
Bisacodyl does not affect any type of contraception, including the combined pill, the progestogen-only pill and emergency contraception.
But if you have severe diarrhoea for more than 24 hours, your contraceptive pills may not protect you from pregnancy. Look on the pill packet to find out what to do.
Find out more:
Can I drive or ride a bike?
Taking bisacodyl should not affect your ability to drive or ride a bike.
Can I drink alcohol while taking bisacodyl?
Yes, you can drink alcohol with bisacodyl.
Is there any food or drink I need to avoid?
Do not take bisacodyl at the same time as dairy products like milk, cheese or yoghurt. Leave a gap of 1 hour between taking any of these and taking your bisacodyl tablets. The small amount of milk in coffee or tea will not affect your bisacodyl tablets.
If you're constipated it may help to eat less foods such as pastries, cakes, puddings and cheese for a while, as these foods can make constipation worse.
Are there any lifestyle changes that can help with constipation?
You can often improve constipation without having to use laxatives. Before trying bisacodyl, or to stop your constipation coming back, it may help to:
- get more fibre into your diet – aim for about 30g of fibre a day. High-fibre foods include fruit, vegetables and cereals. If you're not used to a high-fibre diet, increase the amount of fibre you eat gradually
- add bulking agents, such as wheat bran, to your diet. These will help make your poo softer and easier to pass (although bran and fibre can sometimes make bloating worse)
- drink plenty of water – this helps to keep poo soft
- exercise regularly – keeping your body active will help to keep your gut moving
- go to the toilet when you need to, rather than holding it in