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Laxatives are a type of medicine that can help you empty your bowels if you're having trouble going to the toilet.
They're widely used to treat constipation if lifestyle changes, such as increasing the amount of fibre in your diet, drinking plenty of fluid and taking regular exercise, haven't helped.
Laxatives are available over-the-counter, without a prescription, from pharmacies and supermarkets.
This topic covers:
The main laxatives used in the UK are:
There are also a number of alternative laxatives that are less commonly used, including bowel cleansing solutions, peripheral opioid-receptor antagonists, linaclotide and prucalopride.
Although laxatives have been around for a long time, there's a lack of high-quality evidence about exactly how effective they are and whether certain laxatives are better than others.
Unless there's a reason why specific laxatives may be more suitable than others (see below), most adults should try using a bulk-forming laxative first. These usually start to work after about two or three days.
If your stools remain hard, try using an osmotic laxative in addition to – or instead of – a bulk-forming laxative. If your stools are soft, but are still difficult to pass, try taking a stimulant laxative in addition to a bulk-forming laxative.
Osmotic laxatives usually start to work after about two or three days, while stimulant laxatives usually have an effect within six to 12 hours.
Speak to your GP or pharmacist if you're unsure which laxative to use. Also see your GP if you're still constipated after trying all of the different types of laxative, or if you think your child might benefit from taking laxatives.
Although laxatives are available over-the-counter, they're not suitable for everyone.
Laxatives aren't usually recommended for children, unless advised by a doctor, and some types of laxatives may not be safe to use if you have certain conditions, such as Crohn's disease or ulcerative colitis.
Before using laxatives, carefully read the patient information leaflet that comes with the medication to make sure it's safe for you to take.
Read more about the considerations regarding laxatives.
How you take laxative medication depends on the form it comes in, they are commonly available as:
Some laxatives are also designed to be taken at certain times of the day, such as first thing in the morning or last thing at night.
Read the patient information leaflet that comes with your medication so you know how to take it properly. Ask your pharmacist for further advice if you're still not sure how to take your medication.
While taking bulk-forming or osmotic laxatives it's particularly important to stay well hydrated by drinking plenty of fluids. This is because these laxatives can cause dehydration.
Never take more than the recommended dose of laxatives because this can be harmful and cause troublesome side effects (see below).
Ideally, laxatives should only be used occasionally and for short periods of time. Stop taking a laxative when your constipation improves.
After taking a laxative, to help stop constipation returning you can make certain lifestyle changes, such as drinking plenty of water, exercising regularly and including more fibre in your diet. These types of measures are a better way of preventing constipation than excessive use of laxatives.
See your GP for advice if you're often constipated, despite making appropriate lifestyle changes, or if your constipation hasn't improved after taking laxatives for more than a week.
Don't get into the habit of taking laxatives every day to ease your constipation because this can be harmful.
In some cases, you may be prescribed a laxative to use regularly, but this should always be supervised by your GP or a gastroenterologist (a specialist in digestive conditions).
Like most medications, laxatives can cause side effects. They're usually mild and should pass once you stop taking the medication.
The side effects you may experience will depend on the specific medication you're taking, but common side effects of most laxatives include:
Contact your GP for advice if you experience any particularly troublesome or persistent side effects while taking laxatives.
Excessive or prolonged use of laxatives can also cause diarrhoea, intestinal obstruction (where the bowel becomes blocked by large, dry stools) and unbalanced levels of salts and minerals in your body.
It's often possible to improve constipation without having to use laxatives. Before trying laxatives, it may help to make a number of lifestyle changes, such as:
Read more about preventing constipation.