Management of constipation

• Aluminium antacids
• Antimuscarinics (g. procyclidine, oxybutynin)
• Antidepressants (most commonly tricyclic antidepressants, but others may cause constipation)
• Some antiepileptics (g. carbamazepine, gabapentin, oxcarbazepine, pregabalin, phenytoin)
• Sedating antihistamines
• Antipsychotics
• Antispasmodics (g. dicycloverine, hyoscine)
• Calcium supplements
• Diuretics
• Iron supplements
• Opioids
• Verapamil

• Begin by relieving faecal loading/impaction, if present
• Set realistic expectations for the results of treatment of chronic constipation
• Advise people about lifestyle measures — increasing dietary fibre (including the importance of regular meals), adequate fluid intake, and exercise
• Adjust any constipating medication, if possible

• If lifestyle measures are insufficient, or whilst waiting for them to take effect
• For people taking a constipating drug that cannot be stopped
• For people with other secondary causes of constipation
• As 'rescue' medicines for episodes of faecal loading

• Start treatment with a bulk-forming laxative
• It is important to maintain good hydration when taking bulk-forming laxatives. This may be difficult in the elderly
• If stools remain hard, add or switch to an osmotic laxative (use macrogols as first choice and lactulose if macrogols are not effective, or not tolerated)
• If stools are soft but the person still finds them difficult to pass or complains of inadequate emptying, add a stimulant laxative
• Adjust the dose, choice, and combination of laxative according to symptoms, speed with which relief is required, response to treatment, and individual preference
• The dose of laxative should be gradually titrated upwards (or downwards) to produce one or two soft, formed stools per day
• If at least two laxatives (from different classes) have been tried at the highest tolerated recommended doses for at least 6 months, consider the use of 5-HT₄-receptor agonist or guanylate cyclase-C receptor agonist as per their recommended place in therapy

• Advise them to increase the intake of fluid and fruit and vegetables if necessary
• Avoid bulk-forming laxatives
• Use an osmotic laxative and a stimulant laxative
• Adjust the laxative dose to optimise the response
• More information on the pros and cons of the various laxatives, is available within NICE CKS topic on constipation.

If patients is taking more than one laxative, do not stop treatment abruptly. Reduce stimulant first and monitor effect before stopping other laxatives.