For managing IBS symptoms, pharmacological treatments include antispasmodic agents, which should be taken as required alongside dietary and lifestyle advice NICE CKS.
Loperamide is recommended as the first choice of antimotility agent for diarrhoea in IBS NICE CKS.
People with IBS should be advised to adjust their doses of laxatives or antimotility agents according to clinical response, aiming for a soft, well‑formed stool (Bristol Stool Form Scale type 4) NICE CKS.
Consider linaclotide for people with IBS‑constipation if maximum tolerated doses of previous laxatives have not helped and they have had constipation for at least 12 months; follow-up should occur after 3 months NICE CKS.
For persistent symptoms, a trial of antidepressants such as tricyclic antidepressants (TCAs) can be considered, starting at a low dose (5–10 mg equivalent of amitriptyline) taken at night, with regular review NICE CG61.
SSRIs should only be considered if TCAs are ineffective, with similar cautious dosing and follow-up NICE CG61.
Psychological interventions like CBT or hypnotherapy may be considered if pharmacological treatments are ineffective after 12 months NICE CKS.