Why is toddler peeing themselves

Laura

My 3 year old boy has been using the toilet with no issues for a few months. But the past few days has been having lots of accidents. Today he had one literally washed and changed him and within 5 minutes had another. Im not sure whether its a phase they go through or not. I work in a care home so going to take his urine to get one of the nurses to test it tomoro for a uti. Has anyone ever experienced this