The best remedy for constipation is diet, fluids and a little exercise. This treats it and prevents it happening in the long term, so it’s best all round. However if you’re uncomfortable now and can’t wait for longer term solutions to kick in, there are different types of laxatives available that will ease the problem in the short term.
In this article we’ll look at these different types of laxatives.
Note: All medications have a drug name and a brand name. The brand name may vary from country to country. There are some examples of both the drug and brand names here. (The brand names are shown with a Capital Letter and often in brackets after the drug name.)
When should laxatives be used?
Laxatives are usually a short term measure to deal with constipation.
They may be needed in the longer term if lifestyle measures don’t sufficiently deal with the problem. It’s important to make sure that, if you have chronic constipation, you use the right type of laxative and that they aren’t stopped suddenly. Your doctor will be able to advise you about which to use and a trial without laxatives if you have long term constipation problems.
If you have been constipated for some time then there may be some old stools building up in the bowel (called faecal loading) or even some blockage (called impaction). This will need to be dealt with before the bowel will start to work normally. This takes higher doses of laxatives. A lower, maintenance dose, as well as diet and lifestyle, will help to keep things moving as they should.
The 4 main types of laxative:
- Stool softening laxatives.
- Bulk-forming laxatives increase the amount of stool by adding fibre to it. Fibre in the bowel, either through diet or in a laxative, enables the bowel to push its contents along its length.
They take 12-24 hours to work and a few days for their full effect to develop. It’s often recommended that these are tried first.
Bulk-forming laxative brands include:
- Fybogel, Fibrelief, Isogel and Regulan. They contain the ingredient ispaghula.
- Normacol contains sterculia, a similar fibre supplement.
- Celevac contains methylcellulose, also a fibre supplement.
It’s important to drink plenty of fluid when you’re taking these meds as they work by absorbing water into the bowel, making it easier to pass.
Bulk forming laxatives – side effects.
Occasionally these laxatives can make the problem worse, especially if there is some faecal loading (see above).
They can make the abdomen feel bloated.
They can cause excess wind in the bowel, causing farting/flatulence. This will lessen in a few weeks as the bowel gets used to the treatment.
- Stimulant laxatives contain chemicals thatcause the muscle in the large bowel (the colon and rectum – see the diagram) to contract and squeeze harder than normal. This pushes the stools along better and makes you want to go to the toilet.
They take about 10-12 hours to work and it’s recommended that you take them before bed so that you can pass your stool when you get up.
Stimulant laxative brands include:
- Senokot and Manevac, which contain senna. Manevac also contains ispaghula (see above).
- Dulcolax contains bisacodyl.
- Dulcolax Perles contain sodium picosulfate.
- Docusol and Dioctyl contain docusate sodium.
Stimulant suppositories are put into the lower bowel and have a quicker effect, working in 20-60 minutes. To use these on yourself, lie on your left side, use some lubricant gel (eg KY) and a disposable plastic glove if you want. Push the suppository into the rectum as far as it will go. Stay lying on your side until you feel the urge to go to the toilet.
If the stools are soft but still difficult to pass, then this laxative may work best.
Stimulant laxatives – side effects:
They can cause abdominal cramping and the sudden urge to rush to the toilet. This can lead to bowel incontinence.
Long term use can make the bowel lazy and not work effectively by itself.
- Osmotic laxatives. You may remember we said earlier that the lower bowel re-absorbs water from the stool. Osmotic laxatives work to prevent this happening so that the stool stays softer and easier to pass.
If there has been no or limited success with bulk-forming laxatives, these may be added or given instead.
Osmotic laxative brands include:
- Duphalac, Lactugal, Regulose, which all contain the drug lactulose.
- Movicol and Laxido contain magrogol. In some countries these are only available on prescription.
Lactulose-based drugs can take up to 48 hours to work so aren’t ideal for quick relief. Magrogols are faster acting and better for faecal loading or impaction.
Magnesium salts and phosphate enemas (liquids or gels that are put into the back passage) are stronger and faster acting. They are often used before bowel surgery.
Osmotic laxatives – side effects:
Abdominal gas and bloating are common.
Some people don’t like the taste of lactulose. It’s a liquid preparation, and magrogols are often in sachet form that are added to water.
- Faecal softener laxatives work by softening and wetting the stools.
Osmotic laxative brands include:
They all contain docusate sodium which also has a mild stimulating effect to the bowel.
Peanut oil as an enema can be given via the back passage as an enema and is also a stool softener.
If you’re worried about your symptoms or medical problem but don’t want to seek professional help because you feel embarrassed, silly or that it’s your fault, read this page now: How to talk to a doctor about an embarrassing problem.