Well, the funeral went very well (if you know what I mean) and brother-in-law went back for the further tests yesterday morning, they still couldn't understand what was wrong so he was allowed out for the funeral then had to go back for a scan. Turns out it was a DVT after all. It had got stuck in his spleen hence the enlargement and in turn this was messing up his white blood count. Luckily they had injected him with warfarin on Friday so the DVT has dispersed. He had a transfusion of three pints of saline today in order that he can fly back on Thursday.
I know we all moan about the NHS from time to time but thank goodness for all the marvellous doctors and nurses out there.