Male, 5 months old, history of blood/mucos in stool. Born at 34 weeks and on Neosure formula. After 2 months started to have maroon/dark red/brown blood and mucus mixed in stool. Switched to Nutramigen and the blood continues. Switched to Elecare and the blood got signif. worse. Switched to Neocate and the stool turned black. There will be small, random spots of regular stool mixed in and on occassion the stool will be about 50/50 black/normal. Lately it has been 97% black. No medications are being taken and there has been no increase in iron. Nutramigen, Elecare, and Neocate all have the same amount of iron. There are no supplements being taken. The consistancy is kind of sticky, but nor tary. The smell is aweful. If it is blood, wouldn t the origin be from the upper GI? (stomach/esoph) If it were coming from there, wouldn t his spit-up have blood in it? (spit-up is white/normal) He sees a pedi. GI who is of no help and hasn t run a single test (no blood tests, stool tests, imaging, etc). We are in the process of switching gastros, but it will take several months to get in to see the new gastro (only one in my town that accepts our insurance) Any ideas on what it may be? Is it something that can wait a few months until the new gastro sees him or should he be taken in to the ER? He doesn t seem to be more uncomfortable than usual, but he is still in some pain/gassy.