There were a number of gag moments in my medical school career (I’m only half way done). It gets harder to make me gag with every subsequent event but it still happens. I’ve never thrown up but one quick gag and then I’m OK. It is not even noticeable to anyone, usually. I just have to take a quick walk around and get a nose of fresh air and then I’m fine. I have a very blunt sense of smell and so it usually takes a combination of factors to set me off. It is pretty unpredictable. But as Qagdop mentioned, it does seem to inoculate you a little to the next nasty thing that comes along.
First was an autopsy as a premed. Guy had committed suicide by CO poisoning, and was still quite pink. Well, when they had cut open his bowel the smell of poop-and-vomit hit me, combined with me watching the tech peel back his face so they could look at his brain, well I gagged.
First year med school. We were in Anatomy Lab, on Halloween. This meant that they were passing out candy while we were exploring the back of the abdominal cavity. Don’t tell OSHA. We all had Blow-Pops in our mouth and we were digging through preserved intestine. We got most of it out, leaving just the posterior peritoneum, which was coated in about an inch of fat/formaldehyde/bits of unknown crap. Well, it kind of looked like a melted butter sauce after a heavy meal, which caused my tank partner to comment that she wished she had some lobster. And my other tank partner was talking about how much money it would take for him to dip his Blow-Pop in there. And I gagged.
Second year medical school, I was taking an arterial blood gas. You stick a needle perpendicular to the radial artery where you can feel a radial pulse on your wrist. I missed and the needle scraped the bone and it gave me the serious, serious willies. It was naasty and I gagged a bit.
A guy comes in with dark tarry stools and my intern does a rectal on him, which surprise comes out dark and tarry. She tells me melena (digested blood in the stool) has a distinctive smell. She takes a big long whiff of her melena-coated finger and says happily “Yup! Melena!” and I gagged a bit.
First incison and drainage of a large abscess on a large man. Kind of tucked in a fold of fat. I cut it, pus squirts everywhere, and then my intern instructs me to take my pinky, stick it in the incision, and whirl it around to break up the loculations. The feel, smell, and sight of that made me gag.
Other times I thought I would definitely be gagging and I didn’t: tamponade on a rectal tear with a full roll of Kerlix, a tumor debulking and obstruction removal on an unprepped bowel, an attempted suicide who was flinging poop at the doctors, other incisions and drainages (even nastier ones), debridement of stinky gangrenous leg stumps, diabetic ketoacidosis kept in a small room with poor airflow (now that is a smell, BTW), a cerebral aneurysm repair gone wrong with blood pumping out of a large hole in a guy’s skull.
I’ve seen others gag, never seen others vomit. My friend got a little woozy and had to have a little lie down after he watched a traumatic spinal tap. But he had no problem after that, either.