Docusate: stool-softening laxative and enema

Docusate softens stool by increasing the amount of water in it, and it also stimulates the muscles of the gut to help move things along. This dual action makes it a useful option for stools that are dry and hard to pass.

The NHS lists dry, difficult stools, haemorrhoids (piles), anal fissures and bowel emptying before stomach X-rays as uses. It is available by prescription and over the counter at pharmacies under names such as Dulcoease, Dioctyl, Docusol and Norgalax.

For capsules the NHS describes 1 capsule three times a day, never more than 5 in a day, swallowed whole with a glass of water. The liquid is taken as two or three 5 ml spoonfuls three times a day, and one tube of enema is usually enough. Follow your label or prescriber for the right amount.

Capsules and liquid take 1 to 3 days, so take them regularly at breakfast, lunch and dinner. The enema is used when a quick effect is needed and works in roughly 5 to 20 minutes.

• Drink 6 to 8 glasses of water or other fluids a day.

• Do not take docusate for more than 5 days unless it is prescribed, and an enema should only be used for a few days at a time.

• If you miss a dose, skip it and take the next at the usual time.

• A single extra dose is unlikely to cause harm; diarrhoea and stomach pain from extra doses usually pass in a day or two.

Most adults and children aged 12 and over can take docusate. Never give it to a child under 12 unless a doctor prescribes it or a pharmacist recommends it.

It is not suitable if you have had an allergic reaction to it or another medicine, an intestinal blockage, stomach pain or nausea and vomiting within the last 24 hours. The enema adds further exclusions: haemorrhoids or rectal bleeding, anal fissures, inflammatory bowel disease such as ulcerative colitis or Crohn's disease, and paralytic ileus.

Nausea, stomach cramps and diarrhoea are the main effects. Simple meals help nausea; if diarrhoea occurs, stop taking it when using it for mild constipation and drink fluids; for cramp, lower the dose, rest, eat smaller meals and use a heat pad. The enema can cause a brief burning around the back passage, and the liquid may burn the mouth or throat, which a drink of water or squash soothes.

Anaphylaxis is rare but needs a 999 call: swelling of the lips, mouth, throat or tongue, wheezing or breathing difficulty, or collapse. See a doctor if pain or bleeding from the back passage persists after an enema. Suspected side effects can be reported through the Yellow Card scheme.

Docusate is occasionally used in pregnancy and there is no evidence of harm to the baby, though other laxatives with stronger safety evidence, such as lactulose and Fybogel, are usually suggested first after diet, fluids and gentle exercise. It is acceptable while breastfeeding if lifestyle changes fail, for the shortest time, since only a tiny amount is likely to reach milk. There is no evidence it affects fertility.

The one named interaction is mineral oil laxatives such as liquid paraffin, which should not be taken with docusate. There is not enough information on herbal remedies, so tell your pharmacist about everything you use.

You can drink alcohol, drive and ride a bike, and eat normally. Pastries, puddings, sweets, cheese and cake tend to worsen constipation, while around 30 g of fibre a day, fluids and exercise help, introduced gradually.

Prolonged laxative use can cause chronic diarrhoea and a salt imbalance leading to muscle spasms, twitching or seizures, and can weaken natural bowel function, so see a doctor if constipation lasts beyond a week.