AbstractAimPersistent diarrhoea continues for at least 14 days and kills more children than acute diarrhoea. We assessed whether rice suji, green banana mixed rice suji or 75% rice suji improved persistent diarrhoea in young children.MethodsThis open‐labelled randomised controlled trial was carried out between December 2017 and August 2019 at the Dhaka Hospital of icddr,b, Bangladesh, with 135 children aged 6–35 months with persistent diarrhoea. The children were randomly assigned to green banana mixed rice suji, rice suji or 75% rice suji, with 45 in each group. The primary outcome was the percentage who recovered from diarrhoea by day 5 using an intention‐to‐treat analysis.ResultsThe children's median age was 8 months (interquartile range: 7–10 months). By day 5, the recovery rate was 58%, 31% and 58% for children in the green banana mixed rice suji, rice suji and 75% rice suji groups, respectively. The green banana mixed rice suji group had fewer relapses (7%) than the 75% rice suji group (24%). Enteroaggregative Escherichia coli, rotavirus, norovirus, Enteropathogenic Escherichia coli, astrovirus and Campylobacter were the major pathogens for persistent diarrhoea.ConclusionGreen banana mixed rice suji was the most effective option for managing persistent diarrhoea in young children.