Constipation in Adults

Overview

This updated summary of the NICE Clinical Knowledge Summary on constipation includes sections on: advice for those with the condition, management (short-duration and chronic), secondary causes of the condition, and prescribing information. This summary covers recommendations relevant to pharmacists. Refer to the full Clinical Knowledge Summary for a complete set of recommendations.

Reflecting on your Learnings

Reflection is important for continuous learning and development, and a critical part of the revalidation process for UK healthcare professionals. Click here to access the Guidelines Reflection Record.

What Self-management Advice Should I Give?

From age 18 years onwards.

Encourage the Person or Carer to Manage Their Symptoms by Giving Advice on:

• Sources of information and support, such as:
  • the NHS patient information leaflets on Constipation and Bowel incontinence
• 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 minimise 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.
    • The type of fibre is also important: psyllium (or isphagula) husk and coarse wheat bran fibres are more beneficial than finely ground wheat bran fibre.
• 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 these are below the national recommended levels.
• 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 (less than 3 months) constipation:
  • Investigate, exclide and then manage any underlying secondary cause of constipation, if appropriate and possible, and advise the person to reduce or stop any drug treatment that may be causing or contributing to symptoms. This is more likely to be challenging in some elderly people where multimorbidity and polypharmacy are issues.
  • Identify if faecal impaction is present as this will need treatment to resolve and may need enemas, suppositores or disimpaction.
  • Advise on lifestyle measures, such as increasing dietary fibre, ensuring adequate 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 in the full CKS topic 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.
• 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? in the full CKS topic for more information.

Treating Opioid-induced Constipation

• The recommendations on treating opioid-induced constipation are based on expert opinion the document Opioid-induced constipation and bowel dysfunction: a clinical guideline: 
  • 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. Similarly sugar and sugar alcohols eg lactulose and sorbitol, may produce gas and contribute to abdominal distension and discomfort.
  • Osmotic laxatives retain fluid in the stool making defecation easier, and docusate also has stool-softening properties, although the evidence base for docusate use is weak.
  • Stimulant laxatives overcome the reduced peristalsis caused by opioid medication.

How Should I Manage Chronic Constipation?

• For the initial management of chronic constipation:
  • Consider, investigate and manage any underlying secondary cause of constipation, and if possible and appropriate advise the person to reduce or stop any drug treatment that may be causing or contributing to symptoms. This is more likely to be challenging in elderly people where multimorbidity and polypharmacy are issues.
  • Advise on lifestyle measures, such as increasing dietary fibre, ensuring adequate fluid intake, and activity levels. Advising a lifestyle change may improve constipation for the future and additionally improve quality of life and contribute to better general health.
  • Identify if faecal loading and/or impaction is present as this will need treatment to resolve and may need enemas, suppositories, or disimpaction.
• 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 in the full CKS topic for more information on laxative choices and factors to consider before prescribing different laxatives.
• Consider treatment with prucalopride 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.
    • See the section on Prescribing information in the full CKS topic for more information on prucalopride and factors to consider before prescribing it.
• 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 according to need. See the section on How should I follow up a person in primary care? in the full CKS topic 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.

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. Avoid long-term use in pregnancy.
  • A history of prolonged use—due to the risk of electrolyte imbalance, such as hypokalaemia. There is a risk of misuse (eg in eating disorders) and rules have changed to limit the number of stimulant laxative medications that can be bought over the counter.
  • Aardiovascular 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).
  • Ischaemic colitis (macrogel).
  • 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

Adverse Effects 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.
  • Macrogol laxatives can cause medications taken one hour before, during and one hour after to be flushed out of the gastrointestinal tract unabsorbed which includes contraceptive pills.
  • Note: excessive doses of laxatives may cause diarrhoea, which if prolonged, may cause electrolyte disturbances such as hypokalaemia.
  • Use of macrogol may result in a potential interactive effect if used with starch-based food thickeners. Macrogol counteracts the thickening effect of starch, resulting in liquefaction of preparations that need to remain thick for people with swallowing problems.

What Are the Secondary Causes?

Possible secondary causes of constipation include:

• Medications:
  • 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.
  • Calcium-channel blockers, such as verapamil.
  • Diuretics, such as furosemide.
• Organic causes:
  • Endocrine and metabolic diseases:
    • Diabetes mellitus (with autonomic neuropathy). See the CKS topics on Diabetes—type 1 and Diabetes—type 2 for more information.
    • Hypercalcaemia and hyperparathyroidism. See the CKS topic on Hypercalcaemia for more information.
    • Hypermagnesaemia.
    • Hypokalaemia.
    • Hypothyroidism. See the CKS topic on Hypothyroidism for more information.
    • Uraemia.
  • Myopathic conditions:
    • Amyloidosis.
    • Myotonic dystrophy.
    • Scleroderma.
  • Neurological conditions:
    • Autonomic neuropathy.
    • Cerebrovascular disease. See the CKS topic on Stroke and TIA for more information.
    • Hirschsprung’s disease. See the CKS topic on Constipation in children for more information.
    • Multiple sclerosis. See the CKS topic on Multiple sclerosis for more information.
    • Parkinson’s disease. See the CKS topic on Parkinson’s disease for more information.
    • Spinal cord injury, tumours.
  • Structural abnormalities:
    • Anal fissures, strictures, haemorrhoids. See the CKS topics on Anal fissure and Haemorrhoids for more information.
    • Colonic strictures (for example following diverticulitis, ischaemia, or surgery). See the CKS topic on Diverticular disease for more information.
    • Inflammatory bowel disease. See the CKS topics on Crohn’s disease and Ulcerative colitis for more information.
    • Obstructive colonic mass lesions (for example due to colorectal cancer). See the CKS topic on Gastrointestinal tract (lower) cancers - recognition and referral for more information.
    • Rectal prolapse or rectocele.
    • Postnatal damage to pelvic floor or third degree tear.
  • Other:
    • Irritable bowel syndrome. See the CKS topic on Irritable bowel syndrome for more information.
    • Slow transit constipation.
    • Pelvic or anal dyssynergia.