Constipation

Question 1

The Rome III criteria define constipation as

Answer 1

Having 2 or more of the following, for at least 12 wks:

infrequent bowel action <3 per week

feeling of unsatisfied emptying of bowel >25% of time

passage of lumpy or hard stools at least 25% of time

use of manual manoeuvres >25% of time

sensation of anorectal blockage >25% of time Colorectal cancer must be ruled out in adults.

Question 2

Alarm symptoms

Answer 2

Recent constipation in >40 years of age

Rectal bleeding

Family history of cancer

Question 3

Idiopathic (functional) constipation

Answer 3

The commonest type is functional constipation, primarily due to:

1. slow transit, dyssynergic defecation
2. lifestyle e.g.:

• low fluids
• a faulty diet and
• bad habit.

Question 4

Constipation in children

Answer 4

This is defined as having ≥2 of the following over the previous 2 mths:

• <3 bowel motions per wk
• >1 episode of faecal incontinence per wk (previously referred to as encopresis)
• large stools in rectum or palpable on abdominal examination
• retentive posturing and witholding behaviour
• painful defecation

Question 5

Faecal incontinence

Answer 5

This is the passage of stool in an inappropriate place in children who have been toilet trained.

It can present with soiling, due to retention with overflow of liquid faeces (spurious diarrhoea).

Question 6

Management in children

Answer 6

It is nearly always functional (>95%), but rule out:

• Hirschsprung disorder and anal fissure in infants.

Encourage relaxed child–parent interaction with toilet training (e.g. ‘after breakfast habit’ training).

• Advise on correct posture and position.

Establish an empty bowel:

• remove any impacted faeces with microenemas (e.g. Microlax).

Advice for (parents of) children >18 mths:

• –Drink ample non-milk fluids each day (be cautious of cows’ milk)
• –Use prune juice (contains sorbitol)
• –Get regular exercise (e.g. walking, running, outside games or sport)
• –Eat high-fibre foods (e.g. high-fibre cereals, wholegrain bread, fresh fruit with skins left on where possible, dried fruits such as sultanas, apricots or prunes, fresh vegetables)

Use a pharmaceutical preparation as a last resort to achieve regularity.

• If constipation is of brief time treat for 3 mths, if chronic treat for 6 mths.

First line: osmotic laxative, e.g. lactulose: 1–5 yrs: 10 mL/day

• –>5 yrs; 15mL/day
• –>12 yrs: 15 mL bd or

Macrogol 3350 with electrolytes (Movicol):

• –2–12 years: 1 sachet Movicol half daily
• –>12 years: 1 sachet Movicol daily

Consider stool softeners: paraffin oil, e.g. Parachoc; poloxamer drops.

Question 7

Management in adults

Answer 7

• Similar principles as above
• Patient education, inc. ‘good habit’
• Adequate exercise
• Plenty of fluids (e.g. water, fruit juice)
• Avoid laxatives and codeine compounds
• Optimal bulk diet
• Foods with bulk-forming properties (least to most): potato, banana, cauliflower, peas, cabbage, lettuce, apple, carrot, wheat fibre, bran
• Fruits with natural laxatives include prunes, figs, rhubarb, apricots (e.g. prune juice)
• Cereals with wheat fibre and bran

If unsuccessful:

Bulk-producing agent (e.g. ispaghula—Fybogel, Agiolax), adults:

• 1 sachet in water bd or Benefiber® 2 teaspoons full (o) twice daily (first line)

Macrogol 3350 with electrolytes (Movicol)

• 1–2 sachets dissolved in water once daily

or

lactulose syrup 15–30 mL (o) daily until response then 10–20 mL daily

Question 8

Faecal impaction management

Answer 8

Macrogol—up to 8 sachets for 3 days ± Microlax enema

Avoid stimulant laxatives except for short sharp bursts.

Question 9

Therapeutic agents to treat constipation (with examples)

Answer 9

Hydrophilic bulk-forming agents

• psyllium mucilloid (Agiofibe, Metamucil)
• sterculia (Granocol, Normacol)
• ispaghula (Agiolax, Fybogel)
• methylcellulose (Cellulone)
• wheat bran/dextrin (Benefiber)

Osmotic laxatives

• magnesium sulphate (Epsom salts)
• macrogol 3350 with electrolytes (Movicol)
• magnesium hydroxide (Milk of Magnesia)
• lactulose
• mannitol

Stimulant (irritant) laxatives

• senna (Senokot, sennetabs)
• senna with dried fruits (Nulax)
• cascara
• castor oil
• bisacodyl, e.g. Dulcolax

Stool-softening/lubricating agents

• liquid paraffin (Agarol)
• docusate (Coloxyl)
• glycerine suppositories
• sorbital/sodium compounds (Microlax)