Monday lunchtime ds fell from his Trip Trap high chair - I'm not quite sure how, as I had my back to him, but when I turned round he was on his back on the floor, totally dazed for a while, then crying inconsolably for ages, then falling asleep - which is very unusual for him (he is four). Woke him up after an hour, he was still very subdued and quiet, then he perked up a bit, to then complain about a headache. Gave him Calpol - he projectile vomited three times. We took him straight down to the out of hours doc - who told us it was probably a gastric virus and that in fact ds probably fell ill and therefore fell of his chair! Stunned, but on a silly level wanting to believe him, we went home. Later that night ds woke up and threw up several times again - we took him to A & E and they kept him in for 24 hour monitoring, diagnosis - moderate concussion. Thankfully he's fine now.
All this happened in Germany btw, so it's not just English docs who rely on the "it's prob a virus" line...