DD, 15 months, has had a high fever (anywhere from 38C to almost 40C) for the past couple of days. She hasnt' eaten much at all but nursed constantly, and the fever broke last night. She seems fine today, but her first dirty diaper was not the usual light brown, but black, almost like meconium, with streaks of brown yesterday. I don't know what to make of this...has anyone seen this before? Should I be worried?