Similar to this question on Reddit, which asks for sources, I've heard various claims that during unanesthetized, ceremonial circumcision, the boy can go into neurogenic shock. For example, this article on DrMomma.org states:
Dr. Mark Reiss, long time physician and member of Doctors Opposing Circumcision, discusses ample research which shows us that even those babies who don't scream and cry while being cut apart - even the 4% who do receive anesthesia - still show significant and detrimental physiological changes in body and brain activity. Those who do not scream bloody murder show (on neurological scans) to be lapsing into a state of neurogenic shock and/or coma (which can sometimes occur immediately). To the untrained eye (i.e. the parent who says 'my baby didn't cry') it appears as though the baby has just fallen asleep... How blind we sometimes are.
It is not clear, however, what the "ample research" is or who performed the neurological scans and under what conditions.
Others have said that such claims are hyped up and that ceremonial circumcision is not harmful or very painful and that when babies cry little or not at all it's a sign that it's painful, and that most crying is just from the commotion surrounding the ceremony.
What's the real story?