Like all medicines, macrogol may cause side effects in some people, but many people have no side effects or only minor ones.
Common side effects
These common side effects of macrogol happen in more than 1 in 100 people. There are things you can do to help cope with them:
Diarrhoea
Drink lots of fluids, such as water or squash, to avoid dehydration. Signs of dehydration include peeing less than usual or having dark strong-smelling pee.
Reducing your dose of macrogol may help. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor.
If you take the combined pill or progestogen-only pill and you have severe diarrhoea for more than 24 hours, your contraception may not protect you from pregnancy. Check the pill packet for advice.
Indigestion
Try taking macrogol after food. Talk to a doctor if symptoms do not go away. If you need something to ease the discomfort, try taking an antacid, but do not put off speaking to a doctor.
Stomach pain (rumbles or aches)
Try to rest and relax. It can help to eat and drink slowly and have smaller and more frequent meals. Putting a heat pad or covered hot water bottle on your stomach may also help.
If you're in a lot of pain, speak to a pharmacist or doctor.
Bloating and wind (farting and burping)
Take macrogol between meals instead of before or after them. Try to avoid any foods that may make your symptoms worse. It might also help to eat smaller and more frequent meals, eat and drink slowly, and exercise regularly.
Some pharmacy remedies help wind, such as charcoal tablets or simeticone.
Feeling or being sick (nausea or vomiting)
Try taking macrogol with meals, or mixing your dose with some water or fruit juice. Drink lots of fluids, such as water or squash. If you're being sick, take small, frequent sips to avoid dehydration.
Do not take any other medicines to treat vomiting without speaking to a pharmacist or doctor.
If you take the combined pill or progestogen-only pill and you're being sick, your contraception may not protect you from pregnancy. Check the pill packet for advice.
Sore bottom (anus)
Wash your bottom after each poo and pat it dry with a soft, clean towel.
These side effects usually get better if you reduce the amount of macrogol or after you have had a poo. Talk to a doctor or pharmacist if the side effects bother you or do not go away.
Serious side effects
Call a doctor or call 111 straight away if you get any of these rare but serious side effects:
- severe diarrhoea or vomiting
- feeling more tired than usual
- shortness of breath
- swollen ankles, feet or legs (oedema)
- muscle weakness
- irregular heartbeat
These side effects might mean that there have been changes in the electrolytes in your blood. A doctor can check this with an electrolyte test.
Serious allergic reaction
In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to macrogol.
Immediate action required: Call 999 now if:
- your lips, mouth, throat or tongue suddenly become swollen
- you're breathing very fast or struggling to breathe (you may become very wheezy or feel like you're choking or gasping for air)
- your throat feels tight or you're struggling to swallow
- your skin, tongue or lips turn blue, grey or pale (if you have black or brown skin, this may be easier to see on the palms of your hands or soles of your feet)
- you suddenly become very confused, drowsy or dizzy
- someone faints and cannot be woken up
- a child is limp, floppy or not responding like they normally do (their head may fall to the side, backwards or forwards, or they may find it difficult to lift their head or focus on your face)
You or the person who's unwell may also have a rash that's swollen, raised, itchy, blistered or peeling.
These can be signs of a serious allergic reaction and may need immediate treatment in hospital.
Do not drive yourself to A&E.
The person you speak to at 999 will give you advice about what to do.
Other side effects
These are not all the side effects of macrogol. For a full list see the leaflet inside your medicines packet.
Reporting side effects
You can report any suspected side effect using the Yellow Card safety scheme.
Visit the Yellow Card website for more information about reporting side effects.