Statistical analysis
Information from the database was analysed in a de-identified manner using the REDcap data base system as well as SPSS (v25.0. Armonk, NY: IBM Corp). Variables were summarized as mean and SD, median and interquartile range (IQR) or count and percentage. Incontinence scores are presented as mean values. Paired nonparametric data were analysed using Wilcoxon signed rank sum test and independent categorical data will be analysed with the chi-squared test. In addition, scores of 0 or 1 on The St Marks Questionnaire with regard to solid, liquid, or flatal incontinence were analysed as “no incontinence” respectively, and pre-op and long-term follow-up for these variables were compared using McNemar’s test. Values of P < 0.05 were considered statistically significant.