Sometimes when there's a constipation issue, you get a pattern of hard poop followed by a very soft poop. The hard stuff is poop that's been sitting around in the rectum for a long time, getting firmer and drier with time. The soft stuff is newer poop that is passed when the rectum finally decides to let go.
In short, watch this carefully: if you see a recurrent pattern of hard-soft-hard-soft, and your child starts going longer and longer between poops, go see the doc.
Also, I would cut down on constipating foods like white bread, white flour, apples, bananas, cheese, and cow's milk.
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