Constipation

Diagnostic criteria — Rome (functional constipation)

2 or more of the following for >12 weeks, at least 25% of the time:

• Infrequent passage of stool (<3/week)
• Lumpy/hard stools
• Straining
• Sensation of incomplete evacuation
• Use of manual manoeuvres
• Sensation of anorectal obstruction/blockage

Per Murtagh: consistency matters more than frequency — hard stool passed regularly is a bigger problem than soft stool passed irregularly.

Management

Lifestyle first: adequate fluid intake, regular physical activity, respond promptly to the urge to defecate, good toilet positioning (feet supported/raised).

Laxative ladder (stepwise, review response before escalating):

1. Bulk-forming — psyllium/ispaghula or sterculia; needs adequate fluid intake to work, and can worsen bloating if that’s already a prominent symptom.
2. Osmotic — macrogol (polyethylene glycol, e.g. Movicol, Osmolax) first-line if bulking agents are insufficient; lactulose is an alternative but tends to cause more bloating/flatulence.
3. Stimulant — bisacodyl or senna, generally added or used short-term/intermittently rather than as monotherapy for chronic constipation.
4. Refractory constipation — consider a peripherally acting mu-opioid receptor antagonist (if opioid-induced), or refer for specialist assessment of pelvic floor dysfunction/dyssynergic defecation (biofeedback therapy) or slow-transit constipation.

Investigate (rather than treating empirically) if red flags are present, or if constipation is new-onset in an older patient, refractory to first-line measures, or associated with alarm features.