Peritonitis and Stool Burden on Plain Abdominal Radiographs in Patients on Peritoneal Dialysis

Background: Peritonitis is a significant and troublesome complication of peritoneal dialysis. It is imperative to overcome peritonitis to preserve peritoneal function and prolong peritoneal dialysis. Bacterial translocation from the intestinal tract is the most probable candidate for a bacterial portal of entry in peritonitis associated with peritoneal dialysis, and it has been postulated that constipation may be related to this mechanism. The definition of constipation is based on stool characteristics and subjective evaluation, which is often difficult to assess objectively. Attempts have been made to assess the degree of stool burden with plain abdominal radiographs, which can be obtained routinely. Methods: This was a retrospective study comprising 45 patients who were on peritoneal dialysis at the end of 2020. Patients were divided into two groups according to the median score of stool retention on plain abdominal radiographs. The three-year clinical outcomes of transition to hemodialysis and peritonitis were calculated for each group using the Kaplan-Meier method, and adjusted hazard ratios were calculated using the Cox regression model. Results: There were no significant differences between the two groups in age, gender, diabetes status, dialysis vintage, history of peritonitis, and biochemical parameters. A total of 13 patients (29%) developed peritonitis related to peritoneal dialysis. Of these, 22 patients (49%) were converted to hemodialysis, 1 patient (2%) died, and 1 patient (2%) underwent renal transplantation. The Kaplan–Meier analysis demonstrated that patients in the high-score group exhibited a significantly shorter time to first peritonitis than those in the control group, even after adjusting for confounding factors. However, no significant association was found between radiographic scores and transition to hemodialysis. Conclusion: The stool burden score was evaluated by plain abdominal radiographs and demonstrated a significant independent correlation with the time to first peritonitis, though no such correlation was observed with death or transition to hemodialysis. The results of this study may be utilized to assess the efficacy of potential interventions aimed at reducing peritonitis.