system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does your stomach hurt minutes after getting hit in the gonads?

Balls.
gpt
Testes originally form in the abdomen near the stomach and kidneys.  The  nerves and blood vessels remain attached in that region, even after the balls drop. So when a guy gets kicked in the balls or otherwise has his nuts squished, the pain involved travels up from each testicle into the abdominal cavity, via the spermatic plexus, which is the primary nerve of each testicle, and then to the spine.