T-Rex: Ssh! Come closer!
T-Rex: I know more secrets!
T-Rex: More SECRETS of the MEDICAL PROFESSION!
T-Rex: Okay, so peritonitis is when your peritoneum gets infected, and the peritoneum is basically the lining for your abdominal cavity, where your guts are! So if that's infected, you're going to be in pain whenever your belly moves. And when the doctor walks in the room, he might see how you're sitting, cautious in your movements, guarding your belly, and he might suspect peritonitis. And then he might "accidentally" bump into your bed or chair!
T-Rex: If you start to scream from just that small bump, he'll know the peritonitis is bad!
Utahraptor: But why all the subterfuge?
T-Rex: Well, they can just come up and say "I'm going to shake your belly so tell me if it hurts", but that primes the patient, and they'll be LOOKING to feel pain. The bump can get you an unsolicited result and lets you quickly ascertain degree!
Utahraptor: So if you scream, they suspect bad-times peritonitis.
T-Rex: Yep! And then they'll send you for emergency surgery. Did you know that one of peritonitis' causes is your BOWELS becoming PERFORATED so that RAW SEWAGE sloshes around in your belly?
T-Rex: Man, bodies are nasty! I can TOTALLY SEE why nascent machine intelligences don't wanna hang with us.