Prior appendectomy and the phenotype and course of Crohn’s disease

Figure 1 Characteristics of patients and Crohn’s disease (given as percentages) according to appendectomy status and the time span between appendectomy and diagnosis of Crohn’s disease. Numbers indicate the number of patients in each group. a and ns represent the P value of the comparison between the subgroup and the group of never appendectomized patients (aP < 0.05; ns: not significant).