Hygiene in their school toilet should also be paid attention
to.. Find out from the school management.

Just to be sure. Also pay attention to perineal hygiene.. In cleaning female genital after
poo , u clean from front to back and not back to front so as not
to push in faeces into the vaginal or urethra

Hello Madam! Your best bet is to go to a paediatrician to properly examine
and give accurate diagnosis and treatment. Please, also rule out any case of sexual assault or abuse from peers /school etc.