mucous in baby poop

Stacie
Off the bat, yes I called his doctor today and will be calling again in the morning.
Baby is 14 wks and is formula fed with breast milk supplement. He had 3 liquidy poops today and the last 2 have had mucous in them. I don't think it's a dairy allergy popping up due to being on same formula since about wk 4. My diet hasn't changed. Anyone else have this issue that resolved itself or did the dr prescribe something?