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This summary has been developed for use by community pharmacists under our Guidelines for Pharmacy title, it therefore only covers the information relevant to this setting, and is deliberately concise. Areas covered in the summary include: advice for those with the condition, management (short-duration and chronic), secondary causes of the condition, and prescribing information. Please refer to the full NICE guideline for the complete set of recommendations and references.

What self-management advice should I give?

Encourage the person or carer to manage their symptoms by giving advice on:

  • Sources of information and support, such as:
  • Eating a healthy, balanced diet and having regular meals:
    • The person’s diet should contain whole grains, fruits (and their juices) high in sorbitol, and vegetables.
      • Fruits that have a high sorbitol content include apples, apricots, grapes (and raisins), peaches, pears, plums (and prunes), raspberries, and strawberries.
      • The Association of UK Dietitians has useful Food Fact Sheets on Fibre and Fruit and vegetables - how to get five-a-day.
    • Fibre intake should be increased gradually (to minimize flatulence and bloating) — adults should aim to consume 30 g of fibre per day.
      • Advise the person that the beneficial effects of increasing dietary fibre may take several weeks.
    • Public Health England’s booklet The Eatwell Guide has patient information on eating a healthy, balanced diet.
  • Drinking an adequate fluid intake, especially if there is a risk of dehydration.
    • The Association of UK Dietitians has a useful Food Fact Sheet on Fluid.
  • Increasing activity and exercise levels, if needed.
  • Helpful toileting routines:
    • Advise on a regular, unhurried toilet routine, giving time to ensure that defecation is complete.
    • Advise on responding immediately to the sensation of needing to defecate.
    • Ensure that people with limited mobility have appropriate help to access the toilet and adequate privacy.
    • Ensure the person has access to supported seating if they are unsteady on the toilet.

How should I manage short-duration constipation?

For the management of short-duration constipation:

  • Manage any underlying secondary cause of constipation, and advise the person to reduce or stop any drug treatment that may be causing or contributing to symptoms, if possible and appropriate.
  • Advise on lifestyle measures, such as increasing dietary fibre, fluid intake, and activity levels.
  • If these measures are ineffective, or symptoms do not respond adequately, offer treatment with oral laxatives using a stepped approach:
    • Offer a bulk-forming laxative first-line, such as ispaghula. Note: it is important for the person to drink an adequate fluid intake.
    • If stools remain hard or difficult to pass, add or switch to an osmotic laxative, such as a macrogol.
      • If a macrogol is ineffective or not tolerated, offer treatment with lactulose second-line.
    • If stools are soft but difficult to pass, or there is a sensation of inadequate emptying, add a stimulant laxative.
    • See the section on Prescribing information for more information on laxative choices and factors to consider before prescribing different laxatives.
  • If the person has opioid-induced constipation:
    • Do not prescribe bulk-forming laxatives.
    • Offer an osmotic laxative and a stimulant laxative (or docusate is an alternative which also has stool-softening properties).
  • Advise the person to gradually reduce and stop laxatives once the person is producing soft, formed stool without straining at least three times per week.
  • Arrange to review the person regularly, depending on clinical judgement. See the section on How should I follow up a person in primary care? for more information.

Treating opioid-induced constipation

  • The recommendations on treating opioid-induced constipation are based on expert opinion in a review article.
    • Bulk-forming laxatives are not recommended as their mode of action is to distend the colon and stimulate peristalsis, but opioids prevent the colon responding with propulsive action. This may cause abdominal colic and rarely bowel obstruction.
    • Osmotic laxatives retain fluid in the stool making defecation easier, and docusate also has stool-softening properties.
    • Stimulant laxatives overcome the reduced peristalsis caused by opioid medication.

How should I manage chronic constipation?

  • For the initial management of chronic constipation:
  • If the person has ongoing symptoms despite these measures, offer drug treatment with oral laxatives using a stepped approach. Adjust the dose, choice, and combination of laxatives used, depending on the person’s symptoms, the desired speed of symptom relief, the response to treatment, and their personal preference.
    • Offer initial treatment with a bulk-forming laxative such as ispaghula. Note: it is important for the person to drink an adequate fluid intake.
    • If stools remain hard or difficult to pass, add or switch to an osmotic laxative, such as a macrogol.
      • If a macrogol is ineffective or not tolerated, offer treatment with lactulose second-line.
    • If stools are soft but difficult to pass or there is a sensation of inadequate emptying, add a stimulant laxative.
    • See the section on Prescribing information for more information on laxative choices and factors to consider before prescribing different laxatives.
  • Consider the use of drug treatment with prucalopride or lubiprostone if at least two laxatives from different classes have been tried at the highest tolerated recommended doses for at least 6 months, and failed to relieve symptoms, where invasive treatment (such as suppositories, enemas, rectal irrigation and/or manual disimpaction) is being considered.
    • The prokinetic prucalopride (a selective, high-affinity, serotonin [5HT4] receptor agonist) stimulates gastrointestinal motility. Offer a prescription for 4 weeks and if there is no symptom response following this trial, reconsider the benefit of continuing treatment.
    • The secretory drug lubiprostone (a chloride channel activator) acts locally to increase intestinal fluid secretion and improve colon transit. Offer a prescription for 2 weeks and if there is no symptom response following this trial, reconsider the benefit of continuing treatment.
    • See the section on Prescribing information for more information on prucalopride and lubiprostone and factors to consider before prescribing these laxatives.
  • If the person has opioid-induced constipation:
    • Do not prescribe bulk-forming laxatives.
    • Offer an osmotic laxative and a stimulant laxative (or docusate is an alternative which also has stool-softening properties).
  • Gradually titrate the laxative dose(s) up or down aiming to produce soft, formed stool without straining at least three times per week.
  • Arrange to review the person regularly, depending on clinical judgement. See the section on How should I follow up a person in primary care? for more information.

Choice of laxatives

The aim of laxatives is to increase stool frequency or ease of stool passage by increasing stool water content (directly by osmotic or intestinal secretory mechanisms) or by accelerating bowel transit.

  • Bulk-forming laxatives (containing soluble fibre) act by retaining fluid within the stool and increasing faecal mass, stimulating peristalsis; also have stool-softening properties.
    • Ispaghula husk.
    • Methylcellulose.
    • Sterculia.
  • Osmotic laxatives act by increasing the amount of fluid in the large bowel producing distension, which leads to stimulation of peristalsis; lactulose and macrogols also have stool-softening properties.
    • Lactulose.
    • Macrogols (polyethylene glycols).
    • Phosphate and sodium citrate enemas.
  • Stimulant laxatives cause peristalsis by stimulating colonic nerves (senna) or colonic and rectal nerves (bisacodyl, sodium picosulfate).
    • Senna — hydrolyzed to the active metabolite by bacterial enzymes in the large bowel.
    • Bisacodyl and sodium picosulfate — hydrolyzed to the same active metabolite. Bisacodyl is hydrolyzed by intestinal enzymes; sodium picosulfate relies on colonic bacteria.
    • Docusate — a surface-wetting agent which reduces the surface tension of the stool, allowing water to penetrate and soften it. Also has a relatively weak stimulant effect.
  • Prokinetic laxatives
    • Prucalopride — a selective, high-affinity, serotonin (5HT4) receptor agonist, which stimulates intestinal motility.
  • Secretory laxatives
    • Lubiprostone — a chloride-channel activator which acts locally to increase intestinal fluid secretion and improve colon transit.

Contraindications and cautions

Do not prescribe laxatives if there is suspected:

  • Intestinal obstruction or perforation.
  • Paralytic ileus.
  • Colonic atony or faecal impaction (bulk-forming laxatives).
  • Crohn’s disease or ulcerative colitis.
  • Toxic megacolon.
  • Severe dehydration (bisacodyl).
  • Galactosaemia (lactulose).
  • History of hypersensitivity to peanuts (arachis oil enema).

Prescribe laxatives with caution if there is:

  • Fluid and electrolyte disturbance — discontinue treatment if there are symptoms of fluid and electrolyte disturbance.
  • A history of prolonged use — due to the risk of electrolyte imbalance, such as hypokalaemia.
  • Cardiovascular disease — do not prescribe more than two sachets of full-strength macrogol compound oral powder in any one hour, and advise the person to discontinue if symptoms of fluid and electrolyte disturbance occur.
  • Lactose intolerance (lactulose) — may cause diarrhoea.
  • Ischaemic heart disease or arrhythmias (prucalopride).
  • Movicol is considered high in sodium, this should be taken into account for those people on a low salt diet.

Factors affecting choice of laxative

  • The dose, choice, and combination of laxatives used depends on the person’s symptoms, the desired speed of symptom relief, the response to treatment, and their personal preference.
Table 1: Factors affecting choice of laxative
Laxative Time to effect Points to note
Bulk forming laxatives
Ispaghula (also known as psyllium) 2–3 days Useful first-line choice in adults when it is difficult to get adequate dietary fibre; better tolerated than bran. Must not be taken immediately before bed. Adequate fluid intake is important to reduce the risk of intestinal obstruction. Not recommended for people taking constipating drugs.
Sterculia
Methylcellulose 2–3 days Useful first-line choice in adults when it is difficult to get adequate dietary fibre; better tolerated than bran. Must not be taken immediately before bed. Adequate fluid intake is important, to prevent intestinal obstruction. Tablets swell in the mouth on contact with water.
Wheat or oat bran Finely ground bran can be given as bran bread or biscuits, but these are less effective than unprocessed bran. May be unpalatable. Can be added to food or fruit juice. Often poorly tolerated (causes flatulence and bloating) unless increased slowly, and can be difficult to take enough to be effective on its own. Adequate fluid intake is important.
Osmotic laxatives
Lactulose 2–3 days Some people find it sickly sweet and unpalatable. Adequate fluid intake recommended. If used alone in opioid-induced constipation, it often needs to be given in large doses that cause bloating and colic.
Macrogols (polyethylene glycol) 2–3 days Some people find it difficult to drink the prescribed volume of macrogol. Licensed for use in faecal impaction. Idrolax® does not contain electrolytes. Movicol-Half® contains half the dose and electrolytes of Movicol®.
Surface-wetting laxatives
Docusate sodium 12–72 hours Probably acts both as a softening agent and a stimulant. May be a useful alternative for people who find it hard to increase their fluid intake.
Stimulant laxatives
All stimulant laxatives Usually taken in the evening to produce a bowel movement the following morning.
Senna 8–12 hours Licensed only for short-term use. Syrup is unpalatable.
Sodium picosulfate 6–12 hours Licensed only for short-term use. Syrup is palatable.
Bisacodyl 6–12 hours Licensed only for short-term use. No syrup available.
Rectal laxatives
All rectal laxatives Easy to use if administered correctly. Timing of effect may be more predictable than with oral laxatives; suppositories may be best given after breakfast to synchronize the effect of the gastro-colic response. Some people find them undignified and unpleasant to use. All unlicensed for the treatment of faecal loading/impaction except Relaxit® micro-enema and arachis oil retention enema.
Glycerol suppositories (lubricating and weak stimulant) 15–30 minutes Can be used for hard or soft stools. Licensed for occasional use only. Suppositories must be placed alongside the bowel wall so that body heat causes them to dissolve and distribute around the rectum. Suppositories should be moistened before use to aid insertion. are hygroscopic and also act as a lubricant.
Bisacodyl suppositories (stimulant) 15 minutes to 3 hours Avoid if large, hard stools, as no softening effect. Use for soft stools.
Sodium phosphate and sodium bicarbonate suppositories (Carbalax®) (effervescent) 30 minutes People should be advised that these suppositories work by an effervescent action.
Docusate sodium enema (softener and weak stimulant) 15–30 minutes Can be used for hard or soft stools. Correct administration important to prevent damage to rectal mucosa.
Sodium citrate enema (osmotic) 5–15 minutes Smaller volume (5 mL) than a phosphate enema (130 mL). Useful to remove hard, impacted stools. Correct administration important to prevent damage to rectal mucosa. Licensed for occasional use only. Use with caution in the elderly or people at risk of sodium and water retention.
Phosphate enema (osmotic) 2–5 minutes Useful to remove hard, impacted stools. Correct administration important to prevent damage to rectal mucosa. Licensed for occasional use only. Use of phosphate enemas are contraindicated in people who have signs of dehydration or significant renal impairment, as there is an increased risk of hypernatraemia, hyperphosphataemia, hypocalcaemia, and hypokalaemia. Risk of rectal gangrene in people who are systemically unwell with a history of haemorrhoids.
Arachis oil enema (softener) Retention enema — used overnight and warmed before use. Useful for hard, impacted stools.Should not be used in people with peanut allergy. Licensed for occasional use only.
5HT4-receptor agonists
Prucalopride May be considered for people in whom treatment with other laxatives has failed to produce an adequate response. Should only be prescribed by clinicians experienced in treating chronic constipation. Licensed for use in women and men.
Chloride channel activators
Lubiprostone May be considered for people in whom treatment with other laxatives has failed to produce an adequate response. Should only be prescribed by clinicians experienced in treating chronic idiopathic constipation.
Data from: www.medicines.org.uk [NICE, 2010NICE, 2014Wald, 2016BNF 73, 2017]

Adverse effect of laxatives

Adverse effects of laxatives are generally mild and infrequent, and include:

  • Bulk-forming laxatives — flatulence and bloating. Excessive doses or inadequate fluid intake may cause intestinal obstruction.
  • Osmotic laxatives — abdominal pain or cramps, bloating, flatulence, nausea and vomiting; less commonly dehydration, especially if inadequate fluid intake.
  • Stimulant laxatives — abdominal cramps, diarrhoea, nausea and vomiting. Senna may cause yellowish-brown discolouration of the urine.
  • Prucalopride — headache, nausea, diarrhoea, abdominal pain.
  • Lubiprostone — nausea, diarrhoea, headache.
  • Note: excessive doses of laxatives may cause diarrhoea, which if prolonged, may cause electrolyte disturbances such as hypokalaemia.

What are the secondary causes?

Possible secondary causes of constipation include:

  • Drugs

    • Aluminium-containing antacids; iron or calcium supplements.
    • Analgesics, such as opiates and nonsteroidal anti-inflammatory drugs (NSAIDs).
    • Antimuscarinics, such as procyclidine and oxybutynin.
    • Antidepressants, such as tricyclic antidepressants; antipsychotics, such as amisulpride, clozapine, or quetiapine.
    • Antiepileptic drugs, such as carbamazepine, gabapentin, oxcarbazepine, pregabalin, or phenytoin. Antihistamines, such as hydroxyzine.
    • Antispasmodics, such as dicycloverine or hyoscine.
    • Diuretics, such as furosemide; calcium-channel blockers, such as verapamil.
  • Organic causes

© NICE 2019. NICE CKS on constipation. Available from: cks.nice.org.uk/constipation. All rights reserved. Subject to Notice of rights.

NICE guidance is prepared for the National Health Service in England. All NICE guidance is subject to regular review and may be updated or withdrawn. NICE accepts no responsibility for the use of its content in this product/publication. 

Last updated: June 2019.