Development of Irritable Bowel Syndrome Features Over a 5-year Period

There are few data from longitudinal studies of the gastrointestinal and psychologic features of irritable bowel syndrome (IBS). We studied within-person correlations among features of IBS, along with progression of gastrointestinal (GI) symptoms and quality of life, and factors associated with changes over time. We performed a longitudinal study of 276 patients with IBS in Sweden (70% female; ages, 19–76 years) who completed questionnaires, each year for 5 years, about their GI symptom severity, quality of life, GI-specific anxiety, general anxiety, depression, and coping resources. We performed within-person correlation analyses, latent class growth analysis, and random-intercept cross-lagged panel analysis. Within-person correlations with GI symptom severity were strongest for quality of life (r = –0.56) and GI-specific anxiety (r = 0.47). Progression of GI symptom severity was defined based on 3 classes; the class with the highest mean levels of GI, depression, and (GI-specific) anxiety symptoms at baseline did not improve over the 5-year period, contrary to the other classes. GI-specific anxiety was associated with an increase in GI symptom severity and decrease in quality of life 1 year later (P < .05) but other features of IBS were not. In a 5-year study of patients with IBS in Sweden, we found 3 classes of GI symptom development. We found levels of GI-specific anxiety to associate with GI symptom severity and quality of life 1 year later. Clinicians should be aware of GI-specific anxiety in patients with IBS, to identify patients at risk for lack of long-term symptom improvement with standard medical treatment.