My 5.6 year daughter is having sub 100 degree fever since last 4 days. We are giving her Crocin DS and after medicine fever subsides. But its 4th day and fever is not going. Yesterday from afternoon till late night she has no fever, but again at 1 in the night fever came back. Initially she complained of headache, but now she has no headache. She is bit constipated and haven't passed stool since last 2 days. What should I do.