IBS affects 10â22% of the UK population, with NHS costs over Â£200 million a year. Abdominal pain, bloating and altered bowel habit affect quality of life, social functioning and time off work. Current GP treatment relies on a positive diagnosis, reassurance, lifestyle advice and drug therapies, but many suffer ongoing symptoms. A recent Cochrane review highlighted the lack of research evidence for IBS drugs. Neither GPs, nor patients have good evidence to inform prescribing decisions. However, IBS drugs are widely used: NHS costs 2005 of nearly Â£10 million for mebeverine and over Â£8 million for ispaghula husk. CBT and self-management can be helpful, but poor availability in the NHS restricts its use. Development of web-based CBT could increase access without increased costs. Aims 1) To develop a patient CBT based self-management website for IBS, using material from a previously validated paper-based CBT IBS self-management programme and assess the level of support needed for patients using the website (ie initial 30 minute telephone support session with a nurse or not). 2) To pilot an RCT to assess the effectiveness of the most commonly prescribed medications in UK general practice for IBS: mebeverine (anti-spasmodic) and ispaghula husk (bulking-agent) and of the patient CBT based self-management website.