Star Trek is on the softer side of science fiction. It’s just a sitcom in space. When you watch most series based on books (i.e The expanse), major changes need to be made because it doesn’t translate well to the screen.

Using the expanse as an example, the spacers were supposed to be deformed by our standards. They eliminated all the hard sci-fi elements of their appearance. If a book involves a realistic alien civilization, an adaptation is rarely made

Science fiction is one genre that just doesn’t translate well to the screen. The ideas are too big for a budget and too alien to be adequately depicted. I’m grateful that one man is capable of making twenty hours worth of content in less than a year; it’s more sustainable than millions of dollars being spent on two hours of entertainment.

You’re on the right track, but radiation poisoning is a more likely explanation. It causes severe vomiting and diarrhea. If there ever was a nuclear apocalypse, a lot of people would die in the bathroom.