The role of psychological and biological factors in postinfective gut dysfunction

Abstract

Background-Both psychological and physiological disturbances have been implicated in the aetiopathogenesis of irritable bowel syndrome (IBS). Aims-To investigate how the psychological factors act, and the involvement of infective and physiological factors. Methods-Consecutive patients hospitalised for gastroenteritis reported life events for the previous 12 months, and past illness experiences on standardised questionnaires. They also completed psychometric questionnaires for anxiety, neuroticism, somatisation, and hypochondriasis. In some patients, rectal biopsy specimens were obtained during the acute illness and at three months postinfection. Results-Ninety four patients completed all questionnaires: 22 patients were diagnosed with IBS after their gastroenteritis (IBS+), and 72 patients returned to normal bowel habits (IBS−). IBS+ patients reported more life events and had higher hypochondriasis scores than IBS− patients. The predictive value of the life event and hypochondriasis measures was highly significant and independent of anxiety, neuroticism, and somatisation scores, which were also elevated in IBS+ patients. Rectal biopsy specimens from 29 patients showed a chronic inflammatory response in both IBS+ and IBS− patients. Three months later, specimens from IBS+ patients continued to show increased chronic inflammatory cell counts but those from IBS− patients had returned to normal levels. IBS+ and IBS− patients exhibited rectal hypersensitivity and hyper-reactivity and rapid colonic transit compared with normal controls, but there were no significant diVerences between IBS+ and IBS− patients for these physiological measurements. Conclusion-Psychological factors most clearly predict the development of IBS symptoms after gastroenteritis but biological mechanisms also contribute towards the expression of symptoms. (Gut 1999;44:400-406)

Review article: visceral hypersensitivity in irritable bowel syndrome: molecular mechanisms and therapeutic agents

“…The evidence for the hypothesis that inflammation provides an initial stimulus for a persistent state of hypersensitivity in irritable bowel syndrome (IBS) is growing. Chaudhary and Truelove in 1962 17 first related the symptom onset of 34 out of 130 IBS cases to a bout of gastroenteritis and this has been supported by findings in further studies 18, 19 . Persistence of inflammatory cells and T lymphocytes in colonic biopsies of such patients 18, 19 in post‐infectious IBS (PI‐IBS) and an increase in mast cells seen in the colon and terminal ileum 20, 21 suggest that inflammatory changes are responsible for colonic hypersensitivity.…”

Meta‐analysis: the treatment of irritable bowel syndrome

“…It is generally accepted that IBS‐like symptoms are highly prevalent in the months after cure from infectious enteritis, in particular associated after travel to tropical countries. About 7–30% of patients with infectious diarrhoea can develop IBS 6, 183–185 . Inflammatory infiltration of the intestinal mucosa was observed in IBS subjects after infectious gastroenteritis 6, 186 as well as in other IBS patients 187 .…”

“…About 7–30% of patients with infectious diarrhoea can develop IBS 6, 183–185 . Inflammatory infiltration of the intestinal mucosa was observed in IBS subjects after infectious gastroenteritis 6, 186 as well as in other IBS patients 187 . Among the possible mechanisms of probiotic therapy is the promotion of the endogenous defence barrier of the gut.…”

“…IBS, like many other poorly understood disorders, is viewed as a multifactorial disorder (Figure 1). Symptoms and clinical outcomes may depend on the interaction of several pathogenetic factors including genetics, 2–4 early life events, 5 postinflammatory changes after GI infections, 6 psychosocial impact 7 and food 8 …”

Intestinal permeability in patients with irritable bowel syndrome after a waterborne outbreak of acute gastroenteritis in Walkerton, Ontario

“…Between 5 and 30% of patients who suffer an acute episode of infectious gastroenteritis develop chronic gastrointestinal symptoms despite clearance of the inciting pathogen 1–6 . This common clinical phenomenon, called post‐infectious irritable bowel syndrome (PI‐IBS), was first described over five decades ago 7 .…”