My baby usually has dark green poo as he is formula fed an on two occasions after i have left him with a friend he has had bright yellow poo ?? she has a baby also whom she is breastfeeding and i am freaking out that she has breastfed my baby!! She has joked about it before an my response was that is disgusting an she laughed it off. So just wondering if im jumping to the wrong conclusion or not anyone elses formula fed baby had random yellow poo ??