Background: IBS affects 5-11% of the population of most countries. Prevalence peaks in the third and fourth decades, with a female predominance.Aim: To provide a guide for the assessment and management of adult patients with irritable bowel syndrome.Methods: Members of the Clinical Services Committee of The British Society of Gastroenterology were allocated particular areas to produce review documents. Literature searching included systematic searches using electronic databases such as Pubmed, EMBASE, MEDLINE, Web of Science, and Cochrane databases and extensive personal reference databases.Results: Patients can usefully be classified by predominant bowel habit. Few investigations are needed except when diarrhoea is a prominent feature. Alarm features may warrant further investigation. Adverse psychological features and somatisation are often present. Ascertaining the patients' concerns and explaining symptoms in simple terms improves outcome. IBS is a heterogeneous condition with a range of treatments, each of which benefits a small proportion of patients. Treatment of associated anxiety and depression often improves bowel and other symptoms. Randomised placebo controlled trials show benefit as follows: cognitive behavioural therapy and psychodynamic interpersonal therapy improve coping; hypnotherapy benefits global symptoms in otherwise refractory patients; antispasmodics and tricyclic antidepressants improve pain; ispaghula improves pain and bowel habit; 5-HT3 antagonists improve global symptoms, diarrhoea, and pain but may rarely cause unexplained colitis; 5-HT4 agonists improve global symptoms, constipation, and bloating; selective serotonin reuptake inhibitors improve global symptoms.Conclusions: Better ways of identifying which patients will respond to specific treatments are urgently needed.

BACKGROUND:Obesity is increasingly being recognized as a risk factor for a number of benign and malignant gastrointestinal conditions. However, literature on the underlying pathophysiological mechanisms is sparse and ambiguous. Insulin resistance is the most widely accepted link between obesity and disease, particularly colorectal cancer. The recognition that intra-abdominal fat is immunologically active sheds new light not only on the pathogenesis of obesity-related gastrointestinal conditions, but also on inflammatory conditions such as Crohn's disease. AIM:To describe the biology of adipose tissue, its impact on the immune system and explores the possible underlying mechanisms linking obesity to gastrointestinal diseases. It also looks at the role of mesenteric fat in determining severity and course of Crohn's disease. METHODS:Relevant English-language literature and abstracts cited on MEDLINE database were reviewed. RESULTS:Our recent finding of an association between obesity and subclinical bowel inflammation suggests that, apart from promoting generalized immune activation, fat also evokes local immune responses. We propose that the proinflammatory milieu promoted by obesity could underlie many of these associations and that the mechanism implicating insulin resistance may merely represent an epiphenomenon. In Crohn's disease, on the other hand, intra-abdominal fat may provide a protective mechanism. CONCLUSION:The potential of adipose tissue as a therapeutic target is vast and needs exploration.

Irritable bowel syndrome (IBS) has confounded clinicians for over a century. “Mucous colitis” was first described by Osler in 1892. He wrote of a disorder characterised by the passage of tubular casts of the colon, consisting of mucus (mucorrhoea), cell debris, and “intestinal sand”. Osler stated that the colonic epithelium was normal and that many of the patients were hysterical, hypochondriac, or depressed, and suffered from colicky abdominal pains. This condition was also recognised by Hurst, but the disease they described seemed to have disappeared from both clinical practice and medical texts by the late 1920s. The term “mucous colitis” persisted with a new definition, such that by 1928 it described only colonic spasm. The term “irritable colon” first appeared in published research in 1929 when Jordan and Kiefer used it to describe a colonic musculoneural disturbance present in 30% of gastroenterology outpatients. Irrritable colon described abdominal pain and disordered defaecation; it thus had a meaning similar to its present one.