Constipation (Adults)

NICE CKS Constipation. Last revised: Jun 2025.

Guidelines

Advise the following to all patients:
  • Eating a healthy balanced diet containing whole grains, fruits and vegetables
  • Increase fibre intake (30g per day)
  • Drink adequate fluids
  • Increase activity and exercise levels (if below recommended levels)
  • Advice on toileting routines
    • Regular, unhurried toilet routine, giving time to ensure that defecation is complete
    • Respond immediately to the sensation of needing to defecate

If lifestyle measures (above) are ineffective, offer treatment with oral laxatives:

  • Step 1: bulk-forming laxative (e.g. ispaghula)
    • Note that a bulk-forming laxative requires the person to drink adequate fluid for it to work
 
  • Step 2: add or switch to osmotic laxative (1st line: macrogol, 2nd line: lactulose)
 
  • Step 3: consider prucalopride
    • To be used in chronic constipation
    • If at least 2 different laxative classes have been tried at the highest dose for at least 6 months

If stools are soft but difficult to pass or there is a sensation of inadequate emptying → add a stimulant laxative

 

Once the patient is able to produce soft, formed stool without straining at least 3 times per week, gradually reduce and stop the laxatives.

 

1st line: osmostic laxative + stimulant laxative
  • Do not offer bulk-forming laxatives

Step 1:
  • Hard stools → oral macrogol (high-dose), then add a stimulant laxative if ineffective after a few days
  • Soft stools → oral stimulant laxative

Step 2 (if oral laxative is ineffective):
  • Suppository (bisacodyl for soft stools, glycerol +/- bisacodyl for hard stools)
  • Mini enema (docusate or sodium citrate)

Step 3:
  • Enema (sodium phosphate or arachis oil)

References

Author: Adams Lau
Reviewer:
Last edited: 11/08/25