Constipation

Scottish Palliative Care Guidelines
Healthcare Improvement Scotland

Constipation is defecation that is unsatisfactory because of infrequent stools, difficult stool passage or seemingly incomplete defecation. Stools are often hard and can be abnormally small or large. Constipation can cause unpleasant symptoms, such as abdominal and rectal pain, distension, nausea and vomiting and other negative effects on the patient’s wellbeing. As well as the physical suffering, constipation can cause psychological distress and agitation in terminally ill patients.

There are many reasons why patients with palliative care needs may develop constipation.

Constipation can be complex and may require specialist advice if standard treatment is not successful.

Assessment

A full assessment of the patient and their symptoms should be made, looking at:

  • normal and current bowel pattern (frequency, consistency, ease of passage, presence of blood or melaena, pain on passing stool)
  • current and previous laxatives taken regularly (or as needed) and their effectiveness
  • clinical features (that may mimic bowel obstruction or intra-abdominal disease):
    • pain
    • nausea and vomiting, anorexia
    • flatulence, bloating, malaise
    • overflow diarrhoea
    • urinary retention
  • possible causes of the constipation (clarify the cause before starting treatment):
    • medication, eg opioids, antacids, diuretics, iron, 5HT3 antagonists, anticholinergics
    • secondary effects of illness (dehydration, immobility, poor diet, anorexia)
    • tumour in, or compressing, the bowel wall
    • damage to the lumbosacral spinal cord, cauda equina or pelvic nerves
    • hypercalcaemia, hypokalaemia, hypomagnesaemia
    • concurrent disease, such as diabetes, hypothyroidism, diverticular disease, anal fissure, haemorrhoids, Parkinson’s disease.

Abdominal examination may identify abdominal pain, faecal loading, ascites. Rectal or stomal examination can be useful to identify hard stool or masses. Consider whether examinations would cause undue stress for the patient.

Management

The aim of management is to achieve regular comfortable defecation without straining, rather than any particular frequency of bowel motion.

General advice

  • Encourage good oral fluid intake (1.5–2 litres per day if the patient is able).
  • Review dietary intake, aiming to increase fibre intake unless contraindicated, such as a bowel obstruction.
  • Ensure the patient has privacy and access to toilet facilities.
  • Encourage daily exercise according to ability.
  • Address any reversible factors contributing to the constipation, however, do not delay treatment of constipation while waiting for the results of investigations, such as blood tests.
  • Reviewing reversible factors includes deprescribing contributing medications where possible, for example:
    • aluminium-containing antacids, iron or calcium supplements
    • analgesics, eg opioids and non-steroidal anti-inflammatory drugs (NSAIDs)
    • antimuscarinics, eg oxybutynin
    • antidepressants, eg tricyclic antidepressants
    • antipsychotics, eg amisulpride, clozapine and quetiapine
    • antiepileptics, eg carbamazepine, gabapentin, oxcarbazepine, pregabalin and phenytoin
    • antispasmodics, eg hyoscine butylbromide
    • antihistamines, eg hydroxyzine
    • diuretics, eg furosemide
  • It is important to coprescribe laxatives when commencing opioids, refer to Choosing and Changing Opioids.
  • Laxative doses should be titrated according to individual response.
  • If the current regimen is satisfactory and well tolerated, continue with this, but review the patient regularly and explain the importance of preventing constipation.
  • Use oral laxatives in preference to alternative routes of administration.

 

Tables are best viewed in landscape mode on mobile devices.

 Laxative Choice

First line:

Stimulant laxative
  • Senna tablets 15 mg to 30 mg, or bisacodyl tablets 5 mg to 10 mg at night.
    • If significant colic occurs, the stimulant should be discontinued, and a surface-wetting or osmotic laxative used instead.

Second line:

Add in surface-wetting/osmotic laxative
  • Macrogol (for example Laxido®) (with caution in patients with renal disease given the potassium content) 1 to 3 sachets daily.
    • If severe constipation, consider a higher dose for 3 days.
  • Docusate sodium 100 mg to 200 mg twice daily. Docusate sodium can be used in isolation, however, docusate sodium may not provide additional benefit when combined with senna treatment.

Third line:

Add rectal treatment if the rectum is loaded

(do not give rectal treatment if the rectum is ballooned and empty)

1st. Start with a glycerol suppository and bisacodyl suppository given at the same time, placing the bisacodyl suppository directly against the rectal mucosa

2nd. If no result but the rectum remains loaded then progress to a sodium citrate enema, and then a phosphate enema if no result

3rd. If very hard loading an arachis oil enema (except in those with nut allergy) overnight, followed by a phosphate enema in the morning, may be considered

Choice of laxative (see laxative medicines information chart)

  • Patient preferences should be taken into consideration.
  • Suggested laxative starting doses are provided. These should be titrated as appropriate depending on individual response.
  • For constipation in patients taking opioids that is resistant to standard management, refer to the opioid-induced constipation section.

Patients who are paraplegic or bedbound

  • Adjust laxatives or add constipating medications, such as loperamide, according to individual response, aiming to keep the stool formed, but soft.
  • Commence regular rectal intervention (often referred to as a ’bowel regimen’) every 1 to 3 days to avoid possible impaction leading to faecal incontinence, anal fissures or both.
  • An example of a commonly used bowel regimen involves commencing glycerol and bisacodyl suppositories once daily every 2-3 days and if this is ineffective, considering increasing the frequency of suppositories or escalating management to enema treatment.

Opioid-induced constipation

  • All opioids may cause constipation. Constipation commonly worsens as doses increase.
  • All patients initiated on opioids should be made aware of the risk of constipation and be initially prescribed as-required laxatives. Patients often go on to require a laxative prescription on a regular basis.
  • If pain is stable, but constipation is not responding to standard treatments, consider rotation to fentanyl with specialist advice. This is because fentanyl may be less constipating. Refer to Medicines information | Right Decisions.
  • Peripherally acting µ opioid receptor antagonists (PAMORAs) can relieve constipation while allowing preservation of centrally mediated analgesia.
  • Oral PAMORAs, such as naldemedine or naloxegol, may be considered.
  • Contraindications to PAMORAs include gastrointestinal (GI) obstruction or patients at risk of GI perforation.

Seek specialist palliative care advice if these measures are ineffective.

Should these approaches fail, DO NOT escalate treatment to injectable PAMORAs. This should only be used for opioid-induced constipation under specialist palliative care advice, refer to PAMORAs.

Stop PAMORAs treatment if opioids are stopped.

Practice points

  • The majority of patients with palliative care requirements on opioids need a regular oral laxative, refer to Choosing and Changing Opioids.
  • Review the laxative regimen when opioid medication is commenced, or the dose is changed. This includes increasing use of ‘as-required’ opioid medication.
  • Caution is needed with frail or nauseated patients who may be unable to tolerate the volume of fluid needed for macrogol laxatives to be effective.
  • Bulk-forming laxatives are best avoided in patients with palliative care needs as they are not suitable if the patient has a poor fluid intake and reduced bowel motility.
  • In patients receiving enteral feeding who are constipated, it is important to consider the total volume of fluid intake in 24 hours and adjust water flushes as necessary to maintain adequate hydration and treatment of constipation. Advice should be sought from their dietitian as the enteral feeding product may require review, such as offering a product with a higher fibre content.
  • Lactulose may be considered in patients with liver failure for the prevention and treatment of hepatic encephalopathy, while reducing the bleeding risk. However, as a laxative, it is not effective without a high fluid intake. It can cause flatulence and abdominal discomfort in some patients.
  • If laxative therapy fails, seek specialist palliative care advice for alternative options.
  • Manual evacuation must only be considered if other measures have failed and only if absolutely necessary. Manual evacuation requires consent and should never be attempted without analgesia, sedation or both.
  • Constipation in patients with advanced disease is generally multifactorial in origin. As a result, peripheral opioid antagonists may augment rather than replace laxatives.

Resources

Laxative medicines information chart

Laxative

Starting dose

Time to act

Comments

Stimulant laxatives

Senna

15 mg at night

8–12 hours

Licensed only for short-term use. Tablets can be hard to swallow. Syrup is available.

Bisacodyl

5–10 mg at night

6–12 hours

Licensed only for short-term use. No syrup available.

Sodium picosulfate

5–10 mg at night

6–12 hours

Licensed only for short-term use. Syrup is palatable. May be considered if senna is ineffective or not palatable.

Osmotic laxatives

Lactulose

Refer to End Stage Liver Disease

 

15 ml twice daily

2–3 days

Palatable, although some find it sickly sweet. Adequate fluid intake is recommended (1.5 litres per day). Best to avoid using alone for opioid-induced constipation, as it often needs to be given in large doses that can cause bloating and colic.

Macrogols (eg Laxido®) (caution in those with renal disease given potassium content)

1–3 sachets daily

2–3 days

Some people find it difficult to drink the prescribed volume of macrogol (125 ml per sachet). Licensed for use in faecal impaction (up to 8 sachets per day for a maximum of 3 days). Available in half-strength sachets.

Surface-wetting laxatives

Docusate sodium

100–200 mg twice daily

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 sufficiently to use a macragol. Tablets available. Syrup is unpalatable.

Rectal laxatives

Glycerol suppositories (lubricating and weak stimulant)

4 g

15–30 minutes

Can be used for hard or soft stools. Licensed for occasional use only. Suppositories require body heat to dissolve and distribute around the rectum. Suppositories should be moistened before use to aid insertion.

Bisacodyl suppositories (stimulant)

10 mg

15 minutes to 3 hours

Avoid using alone if presence of large, hard stools as no softening effect. Placing the bisacodyl suppository directly against the rectal mucosa enables it to act on the rectal mucosa.

Sodium citrate microenema (osmotic)

1–2

5–15 minutes

Smaller volume (5 mL) than a phosphate enema (130 mL). Useful to remove hard, impacted stools. Correct administration is important to prevent damage to rectal mucosa. Licensed for occasional use only.

Phosphate enema (osmotic/stimulant)

1

15-30 minutes

Useful to remove hard, impacted stools. Correct administration is important to prevent damage to rectal mucosa. Licensed for occasional use only. Use of phosphate enemas is contraindicated in people who have signs of dehydration or significant renal impairment, as there is an increased risk of hypernatraemia, hyperphosphataemia, hypocalcaemia and hypokalaemia. They can also produce rectal gangrene in ill patients with a history of haemorrhoids.

Arachis oil enema (softener)

1

Retention enema–warmed before use and used overnight

Useful for hard, impacted stools. Should not be used in people with nut allergy. Caution is needed in those with soy allergy because of risk of cross-reaction. Best avoided in bowel obstruction, and only to be considered if advised by a specialist. Licensed for occasional use only.

PAMORAs

Antagonist

Comments

Naldemedine
  • Oral preparation
  • Naldemedine is accepted for use within NHS Scotland for the treatment of opioid-induced constipation in adult patients who have previously been treated with a laxative
  • Initiate with caution in patients over 75 years of age
  • No evidence for benefit if morphine oral equivalent dose is greater than 400 mg per day
  • No evidence for benefit if being treated with partial µ opioid agonists, such as buprenorphine

Naloxegol
  • Oral preparation
  • Naloxegol is accepted for use within NHSScotland for the treatment of opioid-induced constipation in adult patients who have had an inadequate response to laxative(s)
  • 25 mg tablet daily in the morning, reduced to 12.5 mg daily in moderate-severe renal impairment. Not recommended in severe hepatic impairment.
  • When naloxegol therapy is initiated, it is recommended that all currently used maintenance laxative therapy should be halted until clinical effect of naloxegol is determined.

Methylnaltrexone
  • Subcutaneous injection
  • Methylnaltrexone is accepted for restricted use within NHS Scotland for treatment of opioid-induced constipation in advanced illness patients who are receiving palliative care when response to usual laxative therapy has not been sufficient. It is restricted to use by physicians with expertise in palliative care.
    • Subcutaneous injection dose according to weight of patient
    • Contraindicated in severe renal/hepatic failure

References

Candy B, Jones L, Larkin PJ, Vickerstaff V, Tookman A, Stone P. Laxatives for the management of constipation in people receiving palliative care. 2015 [cited 2018 Oct 03]; Available from: https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD003448.pub4/full#0.

Clemens KE, Faust M, Jaspers B, Mikus G. Pharmacological treatment of constipation in palliative care. Curr Opin Support Palliat Care. 2013;7(2):183-91. Available from: https://nhs.primo.exlibrisgroup.com/permalink/44NHSS_INST/nf660i/cdi_proquest_miscellaneous_1466094616

Connolly M, Larkin P. Managing constipation: a focus on care and treatment in the palliative setting. Br J Community Nurs. 2012;17(2):60, 2-4, 6-7. Available from: https://doi.org/10.12968/bjcn.2012.17.2.60

Mori M, Ji Y, Kumar S, Ashikaga T, Ades S. Phase II trial of subcutaneous methylnaltrexone in the treatment of severe opioid-induced constipation (OIC) in cancer patients: an exploratory study. Int J Clin Oncol. 2017;22(2):397-404. Available from: https://doi.org/10.1007/s10147-016-1041-6

National Institute for Health and Clinical Excellence (NICE). Naloxegol for treating opioid induced constipation TA345. 2015 [cited 2018 Oct 03]; Available from: https://www.nice.org.uk/guidance/ta345.

National Institute for Health and Clinical Excellence (NICE). Palliative care – constipation. Clinical Knowledge Summary 2024. Available from https://cks.nice.org.uk/topics/palliative-care-constipation/

Sutherland A, Hami F, Maggs J. Cochrane systematic review highlights the importance of lactulose in the management of hepatic encephalopathy. BMJ Support Palliat Care. 2018 Jun;8(2):238-239. doi: 10.1136/bmjspcare-2016-001255. Epub 2016 Dec 13. PMID: 27965213.Tarumi Y, Wilson MP, Szafran O, Spooner GR. Randomized, double-blind, placebo-controlled trial of oral docusate in the management of constipation in hospice patients. J Pain Symptom Manage. 2013 Jan;45(1):2-13. https://doi.org10.1016/j.jpainsymman.2012.02.008

Wilcock A, Howard P, Charlesworth S. Palliative Care Formulary, 8th ed. England: Pharmaceutical Press; 2022. Available from: Medicines Complete: Palliative Care Formulary

How this guideline was developed

This guideline was published in 2025. It updates the constipation guideline from 2019. The update is based on a systematic review of the evidence. Where there were gaps in the evidence advice is based on the expert opinion of the constipation guideline development group.

Constipation guideline development group:

Ms Kelly Moffat (Chair)

Lead Nurse - Palliative Care, NHS Lothian

Ms Erin Gilmour

Pharmacist, NHS Lanarkshire

Ms Ailsa Stein

SIGN Programme Manager, Healthcare Improvement Scotland

Dr Nicola Trotter

Palliative Care Doctor, Strathcarron Hospice, Forth Valley

Dr Ruth Yates

Palliative Medicine Doctor, formerly in NHS Greater Glasgow and Clyde

All members of the guideline development group made declarations of interest.

Consultation

The draft guideline was available on the SIGN website for a month to allow all interested parties to comment.  All comments received were addressed by the guideline development group and recorded in the consultation report.

The Scottish Palliative Care Guideline group are grateful to all those who contributed to the consultation.

 

Editorial

As a final quality control check, the guideline was reviewed by an editorial group to ensure that the reviewers’ comments have been addressed adequately and that any risk of bias in the guideline development process as a whole has been minimised. The editorial group for this guideline was as follows:

Dr Roberta James

SIGN Programme Lead, Healthcare Improvement Scotland

Dr Safia Qureshi

Director of Evidence and Digital, Healthcare Improvement Scotland

Dr Anna Sutherland

Chair, Scottish Palliative Care Guideline

Dr Angela Timoney

Chair of SIGN, Healthcare Improvement Scotland