GI bleeding?

Little one is 5 months and on formula. The past week he has been really irritable. Figured it was teething or gas but nothing helped. Then he would arch his back and kick his legs. At night he randomly screams out. Yesterday he had dark green maybe even a shade of gray dirty diaper and looked like black coffee grounds mixed in. Went to the doctor because he wouldn't stop grunting. Did CBC and answered a ton of questions. New hypoallergenic formula. So far it isn't helping. Appointment in a week. Today the same thing happened but runny diaper still with coffee ground looking specs in it. No bananas. So the odd diapers, grunting, kicking legs, arching back, etc. It's all over not just when wiped. Anyone else? Advice please.