Thanks for posting your query at DoctorSpring.com. I am Dr. Kini and I am pleased to assist you.
Your son is probably having bacillary dysentry. Stool analysis has to be done.
You have to take him to his Pediatrician for further management.
Your son may need a course of antibiotics. For fever I would recommend tylenol and enough fluids. Give probiotics and zinc supplements for faster recovery.
As far as diet is concerned, give him banana, rice, apple sauce and toast.
I hope that answers your question. Please feel free to discuss further.