| Study | Reason for exclusion |
|---|---|
| Amital 2003 | Editorial |
| Aso 1995 | Study about prophylaxis for recurrence of superficial bladder cancer |
| Delia 2002 | No RCT |
| Delia 2002a | Letter to the editor |
| Dugas 1999 | No RCT |
| Fuccio 2012 | Irrelevant to our review question; no RCT |
| Fuccio 2013 | Letter to the editor |
| Garcia‐Peris 2016 | Comparison of prebiotics versus placebo |
| Horowitz 2003 | No RCT |
| Lacouture 2016 | Combined intervention of probiotic and topical alclometasone that was not randomly allocated |
| Liu 2011 | Participants receiving preoperative chemotherapy or radiotherapy were excluded |
| Liu 2013 | Participants receiving preoperative chemotherapy or radiotherapy were excluded |
| Marteau 2001 | Irrelevant to our review question |
| Marteu 2001 | Narrative review |
| McFarland 1994 | Population irrelevant to our review question |
| Mettler 1973 | No RCT |
| Narayan 2010 | Not cancer‐related diarrhoea; no RCT |
| Ohigashi 2011 | No RCT |
| Okawa 1989 | Outcomes irrelevant to our review question |
| Osterlund 2004 | Comparison not of interest |
| Sasidharan 2016 | Prebiotics |
| Visich 2010 | No RCT |
| Zheng 2006 | Children |
RCT: randomised controlled trial.