The aim of this study was to determine the effects of intervention to non-patient with IBS on the short and long term outcomes, and the association between physical exercise and symptoms. The present case controlled study was conducted on 30 adult subjects with mild or moderate symptom of IBS who were allocated randomly to either the exercise (intervention) group (n=15) or the wait-listed control group (n=15). Four-week intervention consisted of components: self record, stretch of abdominal muscle, physical exercise of pelvis, and 15 min working. Measurements (symptom-limited daily life performance, psychological status, CgA, heart rate variability and regional cerebral oxy-hemoglobin change) were performed before and after intervention. Spearman rank correlations were used to assess the association between psycho-physiological data and symptom scores. Wilcoxon rank sum tests compared changes in scores versus their baseline values. After the intervention, tendency of improvements were found in symptom-limited performance of daily life and psychological status. The four-week intervention had immediate beneficial effects on physiological variables and some neurological factors in patients with IBS. The findings of this study could be used as a reference for intervention, education, and physical health policies in IBS. Fibromyalgia is one of the chronic pain syndrome most prevalent worldwide, but there are serious doubts about its origin and its causes yet. Its complexity difficults the diagnosis and, especially, the sick role experience of patients. In this context, showing a maladaptive illness behavior will produce a negative interference in daily lives of these people, increasing their subjective distress. To improve our knowledge about this topic, our pilot study compares the responses between a group of fibromyalgia patients (N=16) and a control group (N=13), all of them women, with a mean age of 44. All participants belonged to a local association (Association of Fibromyalgia of Onda The WHO International Classification of Functioning and Disability (ICF) has been widely accepted as a conceptual model of disablement, but further specification of behavioral factors is required. We proposed conceptualizing disability, or activity limitations, as behavior and integrating biomedical and behavioral determinants. We previously tested a model including constructs from ICF and Social Cognitive Theory (SCT) using structural equation modelling; it fitted better and explained more variance than ICF or SCT alone. The current study replicated that study with a new sample from the same population (orthopedic patients awaiting joint replacement), and extended the tests to after surgery. Two weeks before surgery, 342 orthopedic patients with chronic pain (most having arthritis) completed a questionnaire assessing impairment and activity limitations plus SCT variables (Self-Efficacy and Outcome Expectancy). One year after surgery, when both impairment and activity limitations were reduced, 228 completed the questionnaire again. We imposed the statistical models found in our previous study (before and after surgery) using structural equation modelling, with NNFI, CFI, RMSEA fit indices) to predict activity limitations. Before surgery, findings were very similar to our previous findings, with all models accounting for significant variance and fitting well, but the integrated model fitted better and accounted for more variance. (ICF: 35%; SCT: 60%; Integrated model: 64%). Each model showed stronger predictions after surgery, with the combined model accounting for most variance (ICF: 52%; SCT: 79%; Integrated model: 82%). On each occasion, all three predictor variables had significant coefficients. The integrated model provides a good explanation of disability in this population, superior to a biomedical or behavioral model alone, and identifies targets for intervention to reduce disability.