Table 7 Suggested sequence of pharmacological treatment for irritable bowel syndrome

Predominant symptom	First line	Second line
Pain	Antispasmodic	Tricyclic antidepressives
	agents	Hypnosis
		Psychological treatments
Diarrhoea	Loperamide	5-HT₃ antagonist*
Constipation	Ispaghula	5-HT₄ agonist*
Bloating with distension	Dietary manipulation	Probiotics
	Polyethylene glycols	5-HT₄ agonist*
Bloating without	Antispasmodic agents	Probiotics
distension		Tricyclics

*No representative of this class of drugs is currently licensed for IBS in Europe but there are other related drugs in development.