Constipation

Definition

Defecation that is unsatisfactory because of infrequent stools, difficulty passing stools, or the sensation of incomplete emptying.

Rome IV diagnostic criteria for constipation include spontaneous bowel movements occurring less than three times a week.

Chronic constipation
symptoms which are present for at least 12 weeks in the preceding six months.

Faecal loading/impaction
retention of faeces to the extent that spontaneous evacuation is unlikely.

Functional (primary or idiopathic) constipation
chronic constipation without a known cause.

Secondary (organic) constipation
constipation caused by a drug or underlying medical condition.

Assessment

  1. Identify any red flag symptoms or signs that may suggest a serious underlying cause, such as colorectal cancer.

  2. The person’s understanding of constipation and their normal pattern of defecation.

  3. The frequency and consistency of stools, including symptoms of faecal impaction and/or incontinence.

  4. Associated rectal, abdominal, or urinary symptoms.

  5. The severity and impact of symptoms on daily life and functioning.

  6. Any risk factors or secondary causes.

  7. Any self-help measures or drug treatments tried.

  8. Abdominal and internal rectal examination.

Management of chronic constipation

  1. Management of any underlying secondary causes

  2. Advice to reduce or stop any drug treatment that may be causing or contributing to symptoms.

  3. Advice on lifestyle measures, such as increasing dietary fibre, fluid intake, and activity levels.

  4. Management of any faecal loading and/or impaction first, if present
    (hard stool—>macrogol; soft stool—>stimulant; suppositories to act as either mini-enema docusate or ‘full’ sodium phosphate/sodium citrate enema).

Stepwise approach

  1. Bulk-forming laxatives  ispaghula

  2. Add osmotic laxative (stool softener) macrogol or lactulose

  3. Add stimulant laxative senna, biacodyl, docusate

  4. Short-term trial: prucalopride (5HT4-receptor agonist, pro kinetic stimulates intestinal motility, 4w course) or lubiprostone (prostaglandin E1 derivative, promotes intestinal fluid secretion and colonic transit, 2w course) if symptoms persist

 

If the person has opioid-induced constipation:

  1. Do not prescribe bulk-forming laxatives. 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.

  2. Offer an osmotic laxative and a stimulant laxative (or docusate is an alternative which also has stool-softening properties)

  3. Naloxegol 25mg once daily mane, is a peripherally acting opioid receptor antagonist.
    It therefore decreases the constipating effects of opioids without altering their central analgesic effects.
    Naloxegol (Moventig®) is recommended as a possible treatment for opioid induced constipation in patients whose response to laxatives is inadequate.

Aim

Titrating the laxative dose(s) up or down aiming to produce soft, formed stool without straining at least three times per week.

Further action if refractory to laxative treatment

  1. Blood tests for full blood count, thyroid function tests, HbA1c, and serum electrolytes and calcium, to look for an underlying cause.

  2. Assessment of whether a defecatory disorder, such as pelvic floor dyssynergia, may be contributory.

  3. Referral to a gastroenterologist or colorectal surgeon for specialist investigations and management should be arranged if:

  • A serious underlying cause such as colorectal cancer is suspected.

  • An underlying secondary cause of constipation is suspected, which cannot be managed in primary care.

  • Symptoms persist or recur despite optimal management in primary care.

Dr Rajesh Varmaconstipation