Suggest Treatment For Pus And Mucous In Stool

Hello sir I am having 1.5 yrs old girl child. Her current weight is 9 kg which is very low. She is having some infection problem like once in a 2 months she is having pus cells, epithical cells, mucus in her stool so i need to stop food like milk, weigh products, fruits. Is there any proper treatment for that???