Astronauts tight-lipped about reason for hospital visit after 235 days in space

No facts, but I'd guess a combination of:

- After the extra time in space, one of the astronaut's bodies had notable problems re-acclimating to 1g. So all 4 get an overnight stay, JIC.

- A rough re-entry & splash-down, leading to concerns about all those 0g-acclimated astronaut bodies.