Written for Stock My Medicine and clinically reviewed by Hajra Dhanchora, MPharm (GPhC 2216990).
Constipation is going less often than usual, passing hard or lumpy stools, or straining and never feeling finished. Fewer than three times a week is the textbook line, but the real test is whether it's changed for you. Here's why it happens, what helps right now, and how to pick a laxative when diet alone isn't shifting things.
Why am I constipated?
Most constipation comes down to a slow, dry bowel: too little fibre, too little fluid, too little movement, and ignoring the urge until it passes. Medicines are the next biggest cause. Codeine and other opioid painkillers constipate almost everyone who takes them for more than a few days; iron tablets, some antacids, antidepressants and blood-pressure tablets can too. Pregnancy, travel, a change in routine, IBS and an underactive thyroid all slow the bowel down.
Can paracetamol or ibuprofen cause constipation?
Paracetamol very rarely does. Ibuprofen occasionally causes constipation, though it's more often blamed for indigestion. If a painkiller is bunging you up, it's almost always the codeine in a combination product such as co-codamol, Solpadeine or Nurofen Plus, not the paracetamol or ibuprofen. Switch to the plain painkiller if you can, and if you need the codeine, plan a laxative alongside it.
How to relieve constipation on the toilet immediately
Position first: feet up on a small stool so your knees are above your hips, lean forward with elbows on knees, and let your tummy relax rather than pushing. Breathe out slowly as you bear down; holding your breath and straining closes the very muscles you need to open. Give it a few minutes, but don't sit for half an hour. Before you go, a warm drink and a walk round the block use the bowel's natural morning reflex, and massaging the abdomen clockwise, from the right hip up, across and down the left, can move things along. If you need something faster than any tablet, a glycerin suppository from the pharmacy usually works within 15 to 60 minutes.
What to take for constipation: the four kinds of laxative
Bulk-forming (Fybogel, ispaghula husk) adds soluble fibre that holds water in the stool. Gentlest, safest for regular use and in pregnancy, but slow: two to three days, and it must be taken with plenty of water. Osmotic (Movicol and other macrogols, lactulose) draw water into the bowel to soften the stool; one to three days, and the sensible first choice for hard, dry stools and for anyone who can't strain. Stimulant (Senokot Max, which is senna, and Dulcolax, which is bisacodyl) make the bowel muscle contract; taken at bedtime they work overnight in 8 to 12 hours, which is why senna tablets are the best-known quick fix. They're for short-term use, as they can cramp and the bowel can get lazy if leant on for weeks. Lubricant (liquid paraffin) coats the stool so it slides; useful after piles or a fissure when straining must be avoided, but strictly short-term and never taken lying down.
Which is the best laxative?
There isn't one; there's the right one for the job. Hard stools that hurt to pass: an osmotic first. Nothing moving at all and you want it sorted by morning: a stimulant tonight, then an osmotic or fibre to keep it moving. Constipation that keeps coming back: bulk-forming fibre daily, with an osmotic in reserve. Taking codeine: start a stimulant or osmotic on day one rather than waiting. Everything mentioned is in our constipation range, and our pharmacist will help you choose if you'd rather ask.
How to stop it coming back
Around 30g of fibre a day (most of us manage 18), built up gradually; two litres of fluid; a walk every day; and going when the urge comes, especially after breakfast, when the bowel is most cooperative. Prunes, kiwis and oats have real evidence behind them. A laxative treats the episode; the routine prevents the next one.
When constipation needs a GP
See a GP if constipation lasts more than two weeks despite treatment, or comes with blood in the stool, unexplained weight loss, severe tummy pain, vomiting, or a persistent change in bowel habit if you're over 50. Constant tiredness and constipation together can be an underactive thyroid. Constipation in a baby under a year, or a child who's also unwell, needs a GP or health visitor rather than a laxative.
Frequently asked questions
How long does it take for a laxative to work?
Stimulants such as senna: 8 to 12 hours, so take them at bedtime. Osmotics such as Movicol: one to three days. Fibre: two to three days. Glycerin suppositories: within the hour.
Can I take laxatives every day?
Fibre and macrogols can be taken daily long-term. Stimulants such as senna and bisacodyl are for occasional use; if you need them most days, see a GP to find out why.
Is it safe to take a laxative in pregnancy?
Bulk-forming fibre and macrogols are the usual choices. Ask a pharmacist before using a stimulant, and avoid liquid paraffin.