Constipation in Adults

Authored by , Reviewed by Dr Adrian Bonsall | Last edited | Meets Patient’s editorial guidelines

This article is for 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.

Treatment of almost all medical conditions has been affected by the COVID-19 pandemic. NICE has issued rapid update guidelines in relation to many of these. This guidance is changing frequently. Please visit to see if there is temporary guidance issued by NICE in relation to the management of this condition, which may vary from the information given below.

For children, see separate Constipation in Children article.

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 adults.[1]Chronic constipation refers to patients who have had symptoms for more than six months.[2]

Constipation 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 survival.[1]

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.[3]

Patients may mean that:

  • Faeces are too hard.
  • They do not defecate often enough for 'inner cleanliness'.
  • Defecation hurts.
  • They have diarrhoea.

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. Ask about diet and drugs.

Always perform a thorough examination of the abdomen, which should include a rectal examination.

Causes of Constipation
Common causesLow-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 diseaseAnal fissure.
Anal stricture.
Rectal prolapse.
Intestinal obstructionStrictures (eg, Crohn's disease).
Colorectal carcinoma.
Pelvic mass (eg, fetus, fibroids).
Diverticulosis (rectal bleeding is a more common presentation).
Congenital abnormalities.
Lead poisoning.
DrugsOpioid analgesics (eg, morphine, codeine).
Anticholinergics (tricyclics, phenothiazines).
NeuromuscularSpinal or pelvic nerve injury.
American trypanosomiasis, Hirschsprung's disease.
Systemic sclerosis.
Diabetic neuropathy.
Other causesChronic 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.
  • 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.

Drug therapy

Drugs for Constipation
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.
  • Methylcellulose.
  • Sterculia.
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.
Osmotic agents:
  • Retain fluid in the bowel.
  • 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.
  • Macrogols can be used in the long-term management of chronic constipation.
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.


  • Prucalopride is a selective serotonin 5HT4-receptor agonist with prokinetic properties.[5]
  • 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.

Clinical Editor's Comments (September 2017)
Dr Hayley Willacy recently read about treatment options for patients who are not responding to at least two standard laxatives[6]. Where invasive treatment is being considered, lubiprostone enhances intestinal fluid secretion to soften stools and accelerate transit. It may be considered in addition to prucalopride. If treatment with lubiprostone has not worked after two weeks, your doctor will talk to you about whether or not you should keep taking this medicine. Lubiprostone should only be prescribed for you by a doctor who is experienced in treating chronic idiopathic constipation.

  • 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.

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Further reading and references

  1. Ford AC, Talley NJ; Laxatives for chronic constipation in adults. BMJ. 2012 Oct 1345:e6168. doi: 10.1136/bmj.e6168.

  2. Lacy BE, Levenick JM, Crowell M; Chronic constipation: new diagnostic and treatment approaches. Therap Adv Gastroenterol. 2012 Jul5(4):233-47. doi: 10.1177/1756283X12443093.

  3. Constipation; NICE CKS, October 2015 (UK access only)

  4. Prucalopride for the treatment of chronic constipation in women; NICE Technology Appraisal Guidance, December 2010

  5. Liu LW; Chronic constipation: current treatment options. Can J Gastroenterol. 2011 Oct25 Suppl B:22B-28B.

  6. Lubiprostone for treating chronic idiopathic constipation; NICE Technology Appraisal Guidance, July 2014

  7. Stapled transanal rectal resection for obstructed defaecation syndrome; NICE Interventional Procedure Guidance, June 2010

Hello all. I am a 28 year old female that has been chronically constipated for the past 4 years. I have had 3 CT scans and all had come out clear. In early 2020 I was only passing a bowel movement...

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