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)

Relative risk of irritable bowel syndrome following acute gastroenteritis and associated risk factors

“…Overall, these findings support the hypothesis that severity of exposure and/or prolonged exposure increases risk of IBS. Previous studies have hypothesized that psychological stress may increase or sustain inflammatory response to infection and increase the risk of IBS [22,26,28,32,[35][36][37]. To evaluate this, we used a prior history of consultation (within 1 year) for psychological and social problems as a proxy indicator for presence of psychological stress.…”

“…Severity of GE (duration of diarrhoea, presence of blood in stools, abdominal cramps, weight loss), younger age and female gender have been associated with increased risk of PI-IBS [21,[28][29][30][31][32][33][34]. Anxiety, depression and major life events have also been identified as potential risk factors with some hypothesizing that these disorders prolong gut inflammation and heighten sensory perception [22,26,28,29,32,[35][36][37]. Several studies have found increased healthcare-seeking behaviors in IBS patients but reasons for this are not well understood [15,16,33,38].…”

Fecal Assays Detect Hypersensitivity to Cow's Milk Protein and Gluten in Adults With Irritable Bowel Syndrome

“…Recently, the role of microscopic inflammation and immune activation in the intestinal mucosa has been elucidated. 3,5,22 Gastrointestinal infections are more likely to initiate IBS-like symptoms 23 inducing mucosal inflammation. Impaired intestinal permeability 24 and a role for mucosal inflammation in regulating the gut-brain axis 25 have also been reported.…”

Treatment of Diarrhea-Predominant Irritable Bowel Syndrome With Mesalazine and/or Saccharomyces Boulardii

“…Alterations in gastrointestinal motor function, enhanced visceral perception of painful stimuli and psychosocial factors are considered as key contributors to symptom generation in IBS (2,23) . Factors that are receiving recent attention include reduced ability to expel intestinal gas, altered central processing of afferent signals and intestinal inflammation.…”