A multilevel data-analytic approach for evaluation of relationships between daily life stressors and symptomatology: patients with irritable bowel syndrome.

Four statistical strategies were used to evaluate whether occurrence of daily stressors increases lower gastrointestinal (GI) symptoms in irritable bowel syndrome (IBS) patients. Across-subject concurrent correlations between weekly stress and symptoms were positive but casually ambiguous and obscured between- and within-subject and occasion relationships. Multiple regressions assessing (weekly and daily) relations showed that prior symptoms predicted subsequent symptoms but that prior and concurrent daily stress had no consistent effects. Idiographic correlations also showed little evidence for a relationship between stress and symptoms. Daily stress did not appear to increase GI symptoms in IBS patients on a general basis. Daily recording methodology, in conjunction with within-subject analytic strategies, is proposed as an innovative approach to examine relations between stress and physical symptomatology.