NZ Formulary

Bulk laxatives

What does it do?

Bulk laxatives are used to treat and prevent constipation.

Before you start

  • Tell your doctor if you have stomach, bowel or swallowing problems.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.
  • If you have noticed a change in bowel habit that continues for longer than 2 weeks, talk to your doctor before taking bulk laxatives.

How should you take it?

Put Normacol® and Normacol Plus® on the tongue and swallow with at least one glass of water. They can also be sprinkled onto soft food (e.g. yoghurt) and then swallowed with water. Do not crush or chew the granules – swallow the granules whole.
Mix Konsyl D®, Metamucil® and Mucilax® in half a glass of water or juice and take immediately followed by a large glass of water.
Make sure you drink the amount of water directed and don't lie down straight after taking bulk laxatives. This is to prevent them blocking your throat or bowel.

What if you forget a dose?

Should an occasional dose be missed it need not be taken later.

Can you take other medicines?

Some medicines available without a prescription may react with bulk laxatives including:

  • other laxatives – discuss this with your pharmacist
  • anti-diarrhoea medicines such as loperamide (e.g. Imodium®)

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products or recreational drugs.

What side effects might you notice?

Side EffectsRecommended action

Stomach upset

Tell your doctor if troublesome

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • Drink plenty of fluids while taking bulk laxatives.
  • Do not take bulk laxatives immediately before going to bed.
  • Bulk laxatives may take a few days to start working.