This study examined the effect of minor daily stressors on the primary indices of Crohn's disease in 10 adult volunteers from a support group for individuals with inflammatory bowel disease. All subjects monitored the occurrence of daily stress concurrently with the signs and symptoms of their disease for 28 days. The results of the regression and between-subject analyses indicate a relation between daily stress and self-rated disease severity in Crohn's disease. The effects of daily stress on signs and symptoms of Crohn's disease were significant even after controlling for the effects of major life events. Individual within-subject correlations, however, indicated that stress and indicators of disease were highly related for only three subjects. The results of the current study therefore suggest that at least for some individuals with Crohn's disease, daily stress is related to self-reported indicators of the illness.