Multiple choice Which of the following is the earliest stool of a mammalian infant? Spraint Meconium Frass Fewmet Reveal answer Fill a bubble to check yourself B Correct answer Explanation Meconium is the earliest stool of a mammalian infant. Unlike later faeces, meconium is composed of materials ingested during the time the infant spends in the uterus: intestinal epithelial cells, lanugo, mucus, amniotic fluid, bile and water.