Barnaby is doing well. He's staying in though (I could have insisted he come home but collecting him tomorrow would be easier and I don't think he will be too fussed either way and it will be easier for them to get meds etc into him). I'm also intending to do a refit of his pen and not even started yet so I get more time. I think it's loose stools they were concerned about, it was a poor line and the nurse who I don't know was difficult to follow. I got told that "the vet" (not named) who has been in charge of his care would rather be on the safe side and monitor him for another day.
Sounds sensible to me both for him and for you to do your refit