AIM: To examine familial aggregation of irritable bowel syndrome(IBS) via parental reinforcement/modeling of symptoms, coping, psychological distress, and exposure to stress.METHODS:Mothers of children between the ages of8 and 15 years with and without IBS were identified through the Group Health Cooperative of Puget Sound.Mothers completed questionnaires,including the Child Behavior Checklist(child psychological distress),the Family Inventory of Life Events(family exposure to stress),SCL-90R(mother psychological distress),and the Pain Response Inventory(beliefs about pain).Children were interviewed separately from their parents and completed the Pain Beliefs Questionnaire(beliefs about pain),Pain Response Inventory(coping)and Child Symptom Checklist[gastrointestinal(GI)symptoms].In addition,health care utilization data was obtained from the automated database of Group Health Cooperative.Mothers with IBS(n=207)and their 296 children were compared to 240 control mothers and their 335 children,while controlling for age and education.RESULTS:Hypothesis 1:reinforcement of expression of GI problems is only related to GI symptoms,but not others(cold symptoms)in children.There was no significant correlation between parental reinforcement of symptoms and child expression of GI or other symptoms.Hypothesis 2:modeling of GI symptomsis related to GI but not non-GI symptom reporting in children.Children of parents with IBS reported more non-GI(8.97 vs 6.70,P<0.01)as well as more GI(3.24 vs 2.27,P<0.01)symptoms.Total health care visits made by the mother correlated with visits made by the child(rho=0.35,P<0.001 for cases,rho=0.26,P<0.001 for controls).Hypothesis 3:children learn to share the methods of coping with illness that their mothers exhibit.Methods used by children to cope with stomachaches differed from methods used by their mothers.Only 2/16 scales showed weak but significant correlations(stoicism rho=0.13,P<0.05;acceptance rho=0.13,P<0.05).Hypothesis 4:mothers and children share psychological traits such as anxiety,depression,and somatization.Child psychological distress correlated with mother’s psychological distress(rho=0.41,P<0.001 for cases,rho=0.38,P<0.001 for controls).Hypothesis 5:stress that affects the whole family might explain the similarities between mothers and their children.Family exposure to stress was not a significant predictor of children’s symptom reports.Hypothesis 6:the intergenerational transmission of GI illness behavior may be due to multiple mechanisms.Regression analysis identified multiple independent predictors of the child’s GI complaints,which were similar to the predictors of the child’s non-GI symptoms(mother’s IBS status,child psychological symptoms,child catastrophizing,and child age).CONCLUSION:Multiple factors influence the reporting of children’s gastrointestinal and non-gastrointestinal symptoms.The clustering of illness within families is best understood using a model that incorporates all these factors. AIM: To examine familial aggregation of irritable bowel syndrome (IBS) via parental reinforcement / modeling of symptoms, coping, psychological distress, and exposure to stress. METHODS: Mothers of children between the ages of 8 and 15 years with and without IBS were identified through the Group Health Cooperative of Puget Sound. Mothers completed questionnaires, including the Child Behavior Checklist (child psychological distress), the Family Inventory of Life Events (family exposure to stress), SCL-90R (mother psychological distress), and the Pain Response Inventory (beliefs about pain) .Children were interviewed separately from their parents and completed the Pain Beliefs Questionnaire (beliefs about pain), Pain Response Inventory (coping) and Child Symptom Checklist [gastrointestinal (GI) symptoms] .In addition, health care utilization data was obtained from the automated database of Group Health Cooperative. Mothers with IBS (n = 207) and their 296 children were compared to 240 control mothers and their 335 ch ildren, while controlling for age and education .RESULTS: Hypothesis 1: reinforcement of expression of GI problems is only related to GI symptoms, but not others (cold symptoms) in children. There was no significant correlation between parental reinforcement of symptoms and child expression of GI or other symptoms. Hypothesis 2: modeling of GI symptoms is related to GI but not non-GI symptom reporting in children. Child of parents with IBS reported more non-GI (8.97 vs 6.70, P <0.01) as well as more GI (3.24 vs. 2.27, P <0.01) symptoms. Total health care visits made by the mother correlated with visits made by the child (rho = 0.35, P <0.001 for cases, rho = 0.26, P <0.001 for controls) .Hypothesis 3 : children learn to share the methods of coping with illness that their mothers exhibit. Methods used by children to cope with stomachaches differed from methods used by their mothers. Ofly 2/16 scales showed weak but significant correlations (stoichiism rho = 0.13, P < 0.05; acceptance rho = 0.13, P <0.05) .Hypothesis 4: mothers and chiPsychological distress correlated with mother’s psychological distress (rho = 0.41, P <0.001 for cases, rho = 0.38, P <0.001 for controls). Hydothesis 5: stress that affects the whole family might explain the similarities between mothers and their children. Family exposure to stress was not a significant predictor of children’s symptom reports. Hypothesis 6: the intergenerational transmission of GI illness behavior may be due to multiple mechanisms. Regression analysis identified multiple independent predictors of the child’s GI complaints, which were similar to the predictors of the child’s non-GI symptoms (mother’s IBS status, child psychological symptoms, child catastrophizing, and child age) .CONCLUSION: Multiple factors influence the reporting of children’s gastrointestinal and non-gastrointestinal symptoms The clustering of illness within families is best understood using a model that incorporates all these f actors.