my 4month old has had regular bm without incident.we started him on cereal about a month ago to slow him down on his formula intake which was almost 8oz at the time. with cereal in his formula he now only takes 4-5oz at a feeding .we started with regular cereal at first,then in the 3rd week we tried oatmeal and banana cereal.he has taken a liking to this so we continued with it. a week ago we started rice and mixed fruit.he seems to take them all without problems but today he had a bm that was a flat dark grey color and thick. his bm have been thick but our concern is the color.