I am trying to prevent uti in my 3 yr old daughter. i will change wet bathing suit. but she goes in and out of the pool for hours. how can a wet bathing suit cause uti vs being in a pool for a long time? is it the fact that it dries on you?

UTI's are generally from fecal contamination - i.e. bacteria from feces enter the urinary tract via the urethra, or from sexual activity or from skin bacteria getting into the area. I do not think being in a wet bathing suit is a major contributor for a UTI though it may be uncomfortable to wear one

Having a we suit on for hours can allow a moisture bridge between the tissues around the anus and the pee outlet. E coli and other fecal germs are normal contaminants of the anal region. If there are enough to move to the pee outlet a UTI can occur. In most girls this is not a problem, but when the fat-pad of the labia shrinks, the outlet is more exposed & it can occur. For some it will/others not