The first poops are the thick, sticky, tarry meconium stools that consist partly of old skin cells shed and then swallowed while the baby is still inside you. These usually look like yellow mustard with little seeds. For any baby, tan, yellow, green, or brown stools can all be normal. By 8 weeks old the average drops to 1 per day. I know many babies who only go every three days.
Breast milk is an amazing food that leaves very little in the way of waste.
Often babies will strain from time to time to move the stool along through the intestines. Straining is usually normal. Crying while straining may be a sign of constipation. When a child is constipated, the stool in the intestines has backed up more than it should. The longer stool sits in the colon, the more water is absorbed back into the body.