My 5 1/2 year old daughter is having to use the restroom sev

My 5 1/2 year old daughter is having to use the restroom several times during the morning in her 3 hours of school. We had her tested for a UTI, but came back negative. One pediatrician told us it is anxiety, but I think it may be something else. She complains about when the class has to sit on the floor. Any suggestions?

It may be due to anxiety as she may be using the bathroom as an excuse to leave the classroom. IS this her first school experience? Sometimes certain foods such as those that have caffeine (chocalate) can irritate the bladder causing a person to go to the bathroom more often. Has her teacher asked her not to leave the classroom so often to go to the bathroom?