It could be due to a forceful letdown which chokes the baby. Changing the nursing position may help. Instead of having the baby lie down, sit the baby in an upright position or lie back (baby is in a tummy time position) to nurse.
This lets baby have more control over the milk flow. There are many factors as to why a baby is agitated when nursing. He could just be tired and sleepy.
My baby gets very frustrated and wails non stop when she is tired AND sleepy at the same time. Most times, she refuses to latch and would rather sleep on a hungry stomach. I have to dreamfeed her after she falls asleep.
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