"Our champion boxer also arrived at one stage, saying that he suffered from a severe attack of diarrhoea. He was in a quandry, he explained, because if he reported sick it might be assumed that he was trying to shirk, and this he did not wish to do under any circumstances. So I advised him, as I think any battalion commander would have done in a similar situation, to tie his waterproof jumping-suit especially tightly from below and to fly and jump with the rest of us.
'You can report sick, my dear fellow, when we get to Crete,' I told him. 'Our medical staff is flying with us.'"
p.51 of "Daedelus Returned," excellent book.