Laxatives
Laxatives can help you empty your bowels if you're constipated. Before taking laxatives you need to be sure that you really are constipated. Normal bowel movements vary from person to person.
If you have cancer, you should always check with your doctor or nurse before taking any type of laxative. They will want to find out what's causing your constipation before recommending treatment for you.
You might not be able to take some types of laxatives if you have a bag on your tummy (a colostomy or ileostomy) to collect your poo.
How you take them
You can buy many laxatives over the counter without a prescription. Other types of laxatives need a doctor’s prescription.
Before buying over the counter laxatives speak to the pharmacist to explain your symptoms, any health problems you may have, and any medicines you are taking. This will help them decide on the best treatment to help you.
It's important to read and follow the information the laxatives come with. Depending on the laxative you have there may be specific instructions. For example, it's important to drink plenty of fluids if you're taking bulk-forming or osmotic laxatives, as they can cause dehydration.
Laxatives come as:
- tablets, capsules or granules that you swallow
- powders that can be made into a drink by adding water or fruit juice
- liquids or gels that you have into the back passage (enemas)
- a capsule (suppositories) that you have into the back passage
Types of laxatives
There are several types of laxatives. Each work in a different way and each are not suitable for everyone.
Your doctor or nurse will want to find out more about your symptoms and the cause of your constipation before they choose the right treatment for you.
Bulk forming laxatives
These work by swelling up inside your bowel and help to soften the poo. This encourages your bowels to move and push the poo out. This type of laxative can take a few days to work properly. Examples include:
- Fybogel
- Sterculia
- Methylcellulose
Stool softener
These work by softening the poo (stool) by drawing more water and fat into the poo. Examples include:
- docusate sodium
- arachis oil enema
Side effects of docusate sodium can include tummy cramps.
Stimulant laxatives
These work by speeding up bowel movements. They can take between 6 and 12 hours to work. Examples include:
- bisacodyl
- senna (Senakot)
- sodium picosulfate
- co-danthrusate
- glycerol suppositories
Osmotic laxatives
These work by drawing more water into your bowel. This makes your poo softer and easier to pass. Examples include:
- lactulose syrup
- macrogols (Movicol and Idrolax)
- magnesium salts (Andrews liver salts, Epsom salts, Cream of magnesia)
Opioid receptor blockers
People having opioid type painkillers often have constipation. Drugs such as methylnatrexone (Relistor) and naloxegol (Moventig) can help. It reduces constipation in people having opioid painkillers when other laxatives have not worked.
Side effects of laxatives
Different laxatives have different side effects.
Bulk forming laxatives can cause wind and a swollen tummy (abdomen). They can also block up your bowel. To prevent this you need to drink plenty of water.
Other types of laxatives can cause stomach cramps and wind. Large doses can cause diarrhoea.
The side effects usually go away once your bowels have opened. But let your doctor or nurse know straight away if you continue to have cramping or abdominal swelling, or if you get diarrhoea.
Taking herbal supplements for constipation
Some herbal medicines claim to be laxatives that can help relieve constipation. Some are safe and do work. But we don’t know exactly how some of these medicines will react with your particular cancer treatments.
Herbal products aren't necessarily all safe. Although they are natural products and you can buy them over the counter at a health shop, some might be harmful to take alongside cancer treatment. So it is very important to let your doctor know if you are planning to take any herbal medicine alongside your cancer treatment.
