Latent structure of irritable bowel syndrome symptom severity

Figure 1 Depiction of the three structural equation models which were tested for the Birmingham irritable bowel syndrome scale. n = 875. All latent variables were fixed to M = 0, SD = 1. Residuals of the manifest variables are omitted for the sake of simplicity. Constip: Constipation; diarrh: Diarrhea; g: General factor of gastrointestinal symptoms.

Figure 2 Percentage of variance of the birmingham irritable bowel syndrome symptom questionnaire items which is explained by the general and specific factors of the final bifactor model.