The aim of this thesis was to evaluate current management and current practice in several anorectal diseases. Part one describes research on haemorrhoidal disease. The clinical effectiveness of RBL versus haemorrhoidectomy in grade II and III haemorroidal disease was assessed in a systematic review and meta-analysis. In order to assess the cost effectiveness of both procedures with emphasis on economic and patient-related outcomes, a protocol for a multicenter, randomised, non-inferiority trial is described. Also, a restrospective analysis was performed in patients with grade III haemorrhoids, who were treated with RBL or haemorrhoidectomy. The number of reinterventions was taken into account as well as the impact of proctologic symptoms on patients’ well-being with patient-reported outcome measurements. The Goligher classification is the most widely used description for haemorrhoidal disease and estimates the severity of prolapse. However, physicians base this gradation on medical history and physical examination and the classification might therefor be prone to interobserver variability. This makes it difficult to evaluate and compare treatment strategies in research. For this reason, the interobserver variability of this classification was assessed among surgeons in the Netherlands. Part II describes two survey studies on current practices in the management of cryptoglandular fistula-in-ano and chronical anal fissures in the Netherlands. In part III several anorectal physiology tests are compared that are used in the diagnostic work-up in patients who are referred for pelvic floor physical therapy, e.g. with faecal incontinence. Lastly, a prospective study is determined were the clinical efficacy of high-volume transanal irrigation (TAI) in patients with constipation and/or faecal incontinence is evaluated.