My 4 month old little girl has been on Similac Alimentum since 2 months old along with cereal in her bottle for reflux. Last week she started have black/dark green tarry sticky thick foul smelling stool. We have exhausted the obvious...she is not on an iron supplement, no blood in her stool, no diet or stress change and no fever...the only thing that she has had is alot of pain,decreased sleep, and increased spitting up from reflux....what could be wrong?