Stress reactivity in childhood functional abdominal pain or irritable bowel syndrome.

BACKGROUND: Frequent abdominal pain (AP) in childhood has been shown to be associated with elevated experience of stress and with deficits in stress coping, but psychophysiological stress reactivity has been studied rarely. METHODS: We examined whether children with frequent AP show altered reactions of the parasympathetic nervous system and the hypothalamic-pituitary-adrenal (HPA) axis during and following an afternoon laboratory social stress task in comparison to healthy children and children with anxiety disorders. Twenty-four children with frequent AP (18 with functional AP and six with irritable bowel syndrome; M = 9.9 years), and 24 healthy controls underwent stressful free speech and arithmetic tasks. Twelve children with anxiety disorders served as second comparison sample. Groups were compared regarding parasympathetic reaction and saliva cortisol concentration. RESULTS: We found no differences in parasympathetic withdrawal between the groups. Concerning the HPA axis, we detected an attenuated cortisol reactivity in children with AP compared to both other groups. CONCLUSIONS: This study provides preliminary evidence that childhood AP is not associated with altered parasympathetic withdrawal during stress. It seems to be related to a down-regulated reactivity of the HPA axis. This pattern was ascertained in comparison to healthy children and also in comparison to children with anxiety disorders. SIGNIFICANCE: Childhood abdominal pain could be related to down-regulated HPA axis reactivity to stress but not to altered parasympathetic reaction. Children with abdominal pain and children with anxiety disorders exhibit a divergent stress-related HPA axis reaction.

Postinfectious irritable bowel syndrome after travelers' diarrhea--a cohort study.

BACKGROUND: There is sound evidence for the role of gastrointestinal infections in the development of postinfectious irritable bowel syndrome (PI-IBS), but understanding the interaction between mental factors and the infection remains incomplete. This study aims to (i) assess the occurrence of PI-IBS in a cohort of patients with self-reported travelers' diarrhea (TD), (ii) assess risk factors for PI-IBS development, and (iii) investigate the prognosis of PI-IBS after 1 year. METHODS: Patients consulting the travel clinic at the University Hospital Tuebingen, Germany (in 2009 and 2010) were identified from records and questioned in follow-ups in 2011 and 2012. We used the Rome III modular questionnaire to assess IBS, the Hospital Anxiety and Depression Scale to assess anxiety and depression, and the Patient Health Questionnaire to assess somatization. KEY RESULTS: We identified 529 eligible subjects from the clinical records. Of 135 subjects (age: 36.6 ± 14.6 years, 58.5% female) included in the study sample 6.7% (95% CI 3.0-11.1) had PI-IBS. We found more females (88.9% vs 56.3%, p = 0.08) and younger age subjects (mean 29.3 vs 37.1 years, p = 0.02) among the PI-IBS subjects. A multivariable regression model revealed vomiting at baseline and high somatization scores as strong and independent PI-IBS risk factors. One year later PI-IBS occurrence decreased to 3.3% (three cases of 90). CONCLUSIONS & INFERENCES: Our findings underline the close linkage of mental and somatic processes for the manifestation of PI-IBS. Screening for psychiatric comorbidities in patients with severe gastrointestinal infections may allow identifying groups at high risk for PI-IBS.

Systematic review with meta-analysis: post-infectious irritable bowel syndrome after travellers' diarrhoea.

BACKGROUND: Gastrointestinal infection is known as a risk factor for the development of the irritable bowel syndrome (post-infectious irritable bowel syndrome, PI-IBS). The incidence of PI-IBS ranges between 3% and over 30% of people after infectious gastroenteritis. AIM: To perform a meta-analysis pools and report data concerning the relative risk (RR) of PI-IBS after TD. METHODS: Database search using Medline through PubMed, Scopus, EBM Reviews (Cochrane Database of Systematic Reviews) and PsycINFO was performed to identify relevant studies. Those that met the inclusion criteria were pooled. A random effects model (Mantel-Haenszel) was performed. RESULTS: Six eligible studies were found. In three of six studies, the authors reported a statistically significant association of TD and PI-IBS. The pooled RR was 3.35 (95% CI: 2.22-5.05) with a significant overall effect (P < 0.00001). Overall PI-IBS incidence was 5.4% in TD subjects and 1.4% in healthy subjects. There was no significant heterogeneity within the pooled studies (I(2)  = 5%). Self-reported TD alone resulted in an over 1.5-fold RR for PI-IBS compared to laboratory-confirmed TD [RR 3.90 (95% CI: 2.35-6.49) vs. RR 2.42 (95% CI: 1.22-4.78)]. CONCLUSIONS: There is a strong association between travellers' diarrhoea and post-infectious irritable bowel syndrome. Self-reports of exposure seem to result in a higher post-infectious irritable bowel syndrome occurrence than laboratory-confirmed cases of travellers' diarrhoea, but further studies are needed to confirm this finding. Finally, potential influences of the selection of an appropriate study population on post-infectious irritable bowel syndrome epidemiology are discussed.

Postinfectious irritable bowel syndrome: follow-up of a patient cohort of confirmed cases of bacterial infection with Salmonella or Campylobacter.

BACKGROUND: Gastrointestinal infections have been proposed to predict subsequent irritable bowel syndrome (IBS) but large-scale infectious events are rare and long-term data are missing. METHODS: We identified 576 individuals with a Salmonella or Campylobacter infection between 2000 and 2009 that were followed by a short postal questionnaire asking for the presence of current symptoms in 2010. In case of agreement (n = 90), an extended postinfectious (PI)-IBS questionnaire was mailed including the Hospital Anxiety Depression Scale and the Patient Health Questionnaire. KEY RESULTS: A total of 189 patients reported back (36%); 98 had a Salmonella and 91 had a Campylobacter infection, of which 56 reported persistent symptoms (9.7% of the initial sample). Fifty-one patients returned the PI-IBS questionnaire. Of 48 patients with complete data, 15 reported no or mild symptoms of abdominal pain or discomfort while 17 had moderate and 16 severe symptoms. Twenty-two met Rome IBS criteria, 14 (29%) reported GI symptoms before the infection. Patients with moderate and/or severe PI-IBS symptoms were significantly more often females, were more often infected by Salmonella than by Campylobacter, had more severe symptoms during the initial infection, and had more often GI symptoms prior to the infection. They reported higher anxiety, depression, and somatisation scores, but were not different with respect to acute stool habits. CONCLUSIONS & INFERENCES: Nearly 10% of patients with an intestinal bacterial infection report postinfectious symptoms up to 10 years after the infectious event. They represent a clinically important population with high psychiatric comorbidity and somatic symptom burden.

Post-infectious irritable bowel syndrome--a review of the literature.

INTRODUCTION: Despite considerable research efforts, the epidemiological characteristics of post-infectious symptoms of the irritable bowel syndrome-type (PI-IBS) are not yet well defined. Estimates of its incidence after gastrointestinal (GI) infection show considerable variation and the number of patients with a history of a GI infection among all patients with IBS is practically unknown. This review aims at summarizing published estimates (i) on the prevalence of PI-IBS among all IBS patients and (ii) on PI-IBS incidence after GI infection, critically discusses methodological differences that may explain the variation of the presented findings and gives an overview on currently identified risk factors for the development of PI-IBS. METHODS: A systematic literature review was perfomed of studies indexed in PUBMED that assessed the epidemiology and risk factors of PI-IBS. RESULTS: The reported incidence of PI-IBS ranges for epidemic infections between 7 and 36 %, for individual infections between 4 and 36 % and for traveller's diarrhea from 4 to 14 %. Estimates of the prevalence of PI-IBS range from as low as 7 % to more than ⅓ of all IBS patients, depending on the study design. The predictors and biomarkers are varying among the studies. CONCLUSION: PI-IBS appears to be common following infectious enteritis and among all IBS patients, but precise estimates are still lacking.