Thread worms creating a big problem....Help please.
One of my relatives is very anxious about the health of her five years old son as he's suffering from thread worms for long. She takes good care of cleanliness and food habits of her child but may be the child is doing something unhealthy in school or his dance classes. She gives him pills prescribed by the doctor but the worms are back within one month. Her child is losing appetite and looks weak and pale. What preventive measures should she take to cure him permanently?