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Constipation in adults

Medical Professionals

Professional Reference articles are designed for health professionals to use. They are written by UK doctors and based on research evidence, UK and European Guidelines. You may find the Constipation article more useful, or one of our other health articles.

For children, see the separate Constipation in Children article.

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Constipation in adults

Chronic constipation is common with a reported prevalence of 14% worldwide, with a significantly higher prevalence in women and people of lower socio-economic status. Symptoms often fluctuate and persistent symptoms over 10-20 years affect only 3% of adults1 . Chronic constipation refers to patients who have had symptoms for more than six months2 .

Constipation in adults can affect quality of life and may be associated with haemorrhoids, anal fissures and serious underlying causes, such as colorectal cancer. Constipation may be associated with a modest reduction in survival1 .

What is constipation3 ?

Constipation is a symptom not a diagnosis and means different things to different people. Always ask patients exactly what they mean by the term constipation. There are various formal (and different) definitions of constipation. It is defined as defecation that is unsatisfactory because of infrequent stools (<3 times weekly), difficult stool passage (with straining or discomfort), or seemingly incomplete defecation. Stools are often dry and hard, and may be abnormally large or abnormally small .

Patients may mean that:

  • Faeces are too hard.

  • They do not defecate often enough for 'inner cleanliness'.

  • Defecation hurts.

  • They have diarrhoea.

In the elderly, consider constipation in any patient presenting with:

  • Confusion or delirium, functional decline.

  • Nausea or loss of appetite.

  • Overflow diarrhoea.

  • Urinary retention.

Faecal loading or impaction should be suspected when there is a history of:

  • Hard, lumpy stools, which may be large and infrequent (for example, passed every 7-10 days), or small and relatively frequent (for example, passed every 2-3 days).

  • A need to use manual methods of faecal extraction.

  • Overflow faecal incontinence, loose stool, excessive wiping or regularly soiled underwear.

Continue reading below

Causes of constipation in adults

Taking a careful history helps to determine the possible cause. Always consider the possibility of a serious underlying cause. Particularly enquire whether there are associated 'red flags' such as weight loss or rectal bleeding.

Ask about frequency, nature and consistency of the stool; whether there is blood or mucus in/on the stools; whether there is diarrhoea alternating with constipation; whether there has been a recent change in bowel habit.

Enquire about accompanying symptoms such as fever, vomiting or loss of appetite.

Ask about a family history of inflammatory bowel disease or bowel cancer.

Assess any risk factors such as:

  • Inadequate dietary fibre or fluids.

  • Lack of exercise.

  • Toileting habits that might predispose to constipation - eg, feeling hurried or being disturbed when trying to defecate; withholding or ignoring the urge to defecate; access to the toilet at home or work, and level of privacy.

  • Anxiety, depression, cognitive impairment, or an eating disorder.

  • Drug treatment or clinical features that might suggest an underlying organic cause of secondary constipation.

Always perform a thorough examination of the abdomen to exclude abdominal tenderness, distension, masses, or a palpable colon (suggesting retained faeces).

A rectal examination should also be performed to exclude:

  • Anal fissures, haemorrhoids, skin tags, rectal prolapse, rectocele, skin erythema or excoriation (may be a sign of faecal leakage).

  • Resting anal sphincter tone; rectal mass lesions and retained faeces (these may also be felt on external palpation around the anus). A faecal mass can be distinguished from a tumour or cyst, as firm pressure exerted by a finger will typically leave a palpable indentation in hard faeces.

  • Pelvic floor dysfunction (if appropriate) - while asking the person to 'bear down', there may be paradoxical contraction of the anal sphincter on straining.

  • Leakage of stool; rectal or anal pain.

Causes of Constipation

Common causes

Low-fibre diet.

Inadequate fluid intake or dehydration.

Immobility (or lack of exercise).

Irritable bowel syndrome.

Elderly age.

Postoperative pain.

Hospital environment (lack of privacy, having to use a bedpan).

Anorectal disease

Anal fissure.

Anal stricture.

Rectal prolapse.

Intestinal obstruction

Strictures (eg, Crohn's disease).

Colorectal carcinoma.

Pelvic mass (eg, fetus, fibroids).

Diverticulosis (rectal bleeding is a more common presentation).

Congenital abnormalities.







Lead poisoning.


Opioid analgesics (eg, morphine, codeine).

Anticholinergics (tricyclics, phenothiazines).



Spinal or pelvic nerve injury.

American trypanosomiasis, Hirschsprung's disease.

Systemic sclerosis.

Diabetic neuropathy.

Other causes

Chronic laxative abuse (rare - diarrhoea is more common).

Idiopathic slow transit.

Idiopathic megarectum/megacolon.


  • Most constipation does not need investigation, especially in young, mildly affected patients.

  • Indications for investigation include:

    • Age >40 years.

    • A recent change in bowel habit.

    • Associated symptoms (weight loss, rectal bleeding, mucous discharge, or tenesmus).

  • Possible investigations include:

    • Blood tests: FBC, U&E, Ca2+, TFTs.

    • Sigmoidoscopy and biopsy of abnormal and normal mucosa.

    • Barium enema if there is suspected colorectal malignancy.

    • Special investigations (eg, transit studies, anorectal physiology) which are occasionally indicated.

Continue reading below

Management3 4

  • Treat the cause.

  • Mobilise the patient.

  • Increase fluid intake; increase intake of high-fibre foods (including fruits, vegetables, whole wheat and bran).

  • Consider drugs only if the above measures fail.

  • Try to use drugs for short durations only.

  • Advise the person to gradually reduce and stop laxatives once they are producing soft, formed stool without straining at least three times per week. Review at regular intervals according to clinical judgement.

Drug therapy

This should be tried in the order listed in the table.

Bulk producers:

Increase faecal mass, which stimulates peristalsis.

They must be taken with plenty of fluid

Contra-indications: difficulty in swallowing; intestinal obstruction; colonic atony; faecal impaction.


Bran powder 3.5 g 2-3 times/day with food.

Ispaghula husk.



Osmotic agents:

Retain fluid in the bowel.

Macrogols can be used in the long-term management of chronic constipation.

Lactulose, a semisynthetic disaccharide,

produces an osmotic diarrhoea of low faecal pH that discourages growth of ammonia-producing organisms. It is useful in constipation (dose: 15 mL/12-hourly) and hepatic encephalopathy (dose: 30-50 mL/12-hourly).

Magnesium salts (eg, magnesium hydroxide and magnesium sulfate) are useful when rapid bowel evacuation is required.

Stool softeners:

Side-effects can include: anal seepage, lipoid pneumonia, malabsorption of fat-soluble vitamins.

Arachis oil enemas lubricate and soften impacted faeces.

Liquid paraffin should not be used for a prolonged period.


Increase intestinal motility and should not be used in intestinal obstruction.

Prolonged use should be avoided, as it may cause colonic atony and hypokalaemia (but there are no good, long-term follow-up studies).

Pure stimulant laxatives are bisacodyl tablets (5-10 mg at night) or suppositories (10 mg in the mornings) and senna (2-4 tablets at night).

Docusate sodium and dantron have stimulant and softening actions; however, dantron is associated with colonic and liver tumours in animals - so reserve its use for the very elderly and the terminally ill.

Glycerol suppositories act as a rectal stimulant.

Sodium picosulfate is useful for rapid bowel evacuation prior to procedures.

Enemas and suppositories - useful additional treatment.

Sodium phosphate enemas and glycerin suppositories may be useful.

Sodium salts should be avoided, as they may cause sodium and water retention.

Phosphate enemas are useful for rapid bowel evacuation prior to procedures.

Excessive use of soapy tap water enemas may lead to water intoxication.


Cheap: senna, bran, co-danthrusate, bisacodyl.

Moderate: magnesium hydroxide, methylcellulose, ispaghula granules, sterculia.

Expensive: lactulose.

Preparations from different groups can be combined - eg, a macrogol and picosulfate.


  • Prucalopride is a selective serotonin 5HT4-receptor agonist with prokinetic properties6 .

  • Prucalopride is recommended as an option for the treatment of chronic constipation only in women for whom treatment with at least two laxatives from different classes, at the highest tolerated recommended doses for at least six months, has failed to provide adequate relief, and invasive treatment for constipation is being considered.

  • If treatment with prucalopride is not effective after four weeks, the woman should be re-examined and the benefit of continuing treatment reconsidered.

  • Prucalopride should only be prescribed by a clinician with experience of treating chronic constipation, who has carefully reviewed the woman's previous courses of laxative treatments.

Obstructed defecation syndrome7

  • Obstructed defecation syndrome (ODS) is characterised by an urge to defecate but an impaired ability to expel the faecal bolus.

  • Symptoms include unsuccessful attempts at faecal evacuation, excessive straining, pain, bleeding after defecation and a sense of incomplete faecal evacuation.

  • Women, especially multiparous women, are more likely than men to present with symptoms of ODS.

  • ODS is often associated with structural defects in the rectum, such as rectocele, internal rectal prolapse and perineal descent.

  • Conservative treatments include diet, biofeedback, laxatives and pelvic floor retraining.

  • Surgery may be considered for patients not responding to conservative treatment or if a structural abnormality is present, Surgical options include stapled transanal prolapsectomy, perineal levatorplasty (STAPL), stapled transanal rectal resection (STARR) and laparoscopic ventral mesh sacrocolporectopexy.

Severe constipation

For patients who fail to respond to conservative measures, other options may be considered.

These include:

  • Transanal irrigation - water is introduced into the rectum by a catheter with inflatable balloon. It is controlled by a manual unit and has a pump, leg straps and a bag to hold the water. It is self-administered by the patient. A number of systems are available (eg, Peristeen®)8 .

  • Sacral nerve stimulation - a minimally invasive procedure whereby an electrode is placed in a posterior foramen of the sacral bone9 10 .

  • The Malone operation - this is also called an antegrade colonic enema (ACE). A small stoma is constructed from the appendix. Through the appendicostomy a catheter is inserted to administer an enema in the caecum. Usually 1.000 mL are given every second day to empty the whole colorectum. In patients who no longer have the appendix, a 'neoappendix' can be created from ileum or part of the caecum10 .

  • Surgery - colectomy with ileorectal anastomosis is reserved for a very small number of patients who do not respond to any other measures10 .

Further reading and references

  1. Ford AC, Talley NJ; Laxatives for chronic constipation in adults. BMJ. 2012 Oct 1;345:e6168. doi: 10.1136/bmj.e6168.
  2. Lacy BE, Levenick JM, Crowell M; Chronic constipation: new diagnostic and treatment approaches. Therap Adv Gastroenterol. 2012 Jul;5(4):233-47. doi: 10.1177/1756283X12443093.
  3. Constipation; NICE CKS, September 2021 (UK access only)
  4. A Guide to Refractory Constipation: Diagnosis and Evidence-Based Management; British Society of Gastroenterology, 2020 - updated November 2021
  5. Prucalopride for the treatment of chronic constipation in women; NICE Technology Appraisal Guidance, December 2010
  6. Liu LW; Chronic constipation: current treatment options. Can J Gastroenterol. 2011 Oct;25 Suppl B:22B-28B.
  7. Stapled transanal rectal resection for obstructed defaecation syndrome; NICE Interventional Procedure Guidance, June 2010
  8. Peristeen transanal irrigation system for managing bowel dysfunction; NICE Medical technologies guidance, February 2018
  9. Maeda Y, O'Connell PR, Lehur PA, et al; Sacral nerve stimulation for faecal incontinence and constipation: a European consensus statement. Colorectal Dis. 2015 Apr;17(4):O74-87. doi: 10.1111/codi.12905.
  10. Krogh K, Chiarioni G, Whitehead W; Management of chronic constipation in adults. United European Gastroenterol J. 2017 Jun;5(4):465-472. doi: 10.1177/2050640616663439. Epub 2016 Aug 2.

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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