Nobody likes to talk about their bowel movements. This squeamishness means that irritable bowel syndrome (IBS), which entails a change in stool form and frequency, is widely under-reported. The condition is comprised of several symptoms, such as diarrhoea or bloating, that are also present in other diseases, complicating efforts to study and treat it. IBS can also be associated with mental-health conditions such as anxiety or depression. In the past, this led some clinicians to categorize it as mainly a psychiatric concern, which for many years also attracted unwarranted stigma. This Outlook describes these difficult issues, the progress made and the challenges that remain (see page S118).
IBS as we now know it has a short history, but it is heavily influenced by work that goes back centuries (S102). Diagnostic capability took a leap forward in the 1980s with the Rome criteria — the fourth iteration is published this month (S107). But what many people want is a reliable diagnostic test (S110), which would also lead to better, more targeted drugs (S116). One subtype of IBS caused by gastroenteritis might already be treatable — or even preventable (S114).
Food can trigger symptoms, and a diet low in FODMAPs — undigestible carbohydrates — has gained many supporters. But not all researchers are convinced of its effectiveness (S108). Something does happen in the large intestine, however, and researchers are trying to decipher the influence of the microbiome on the gut–brain axis (S104). Whatever the cause, one thing is clear — although IBS is mild for many people, for 1 in 20 patients it is a severe and even life-threatening condition. But help is available, and one clinician says that the first step is simply to listen to patients (S112).
We are pleased to acknowledge the support of Allergan plc in producing this Outlook. As always, Nature retains sole responsibility for all editorial content.