Data collection
Data were collected from electronic case report forms. Paper patient diaries were used to collect medication adherence and defecation status data. In the study periods, samples for clinical laboratory tests were collected before or after dialysis, and pre-dialysis samples were obtained right before the first dialysis session of the week. Baseline samples were collected on Day 1 (Week 0) before starting treatment. The parameters at each time point were assessed at a central laboratory.