what could be wrong?

So yesterday afternoon about 5pm I was in the supermarket wth my 4 month old son and he started uncontrollably screaming so I tried him with his bottle, didn't work, we tried cuddles, playing, everything and the only thing that worked was walking round and round in circles at the bus stop, anyway he was fine on the bus home, had his bath and milk and went to bed at 8 as normal, woke up at half 11 and started screaming again and this time wouldn't stop, me, my fiancée and my nan all tried to get him to stop and my nan eventually got him to take his bottle and go to sleep after a full hour of screaming but then he woke up 3 more times during the night for a bottle (no screaming) which is unusual for him as he normally sleeps through, what could be wrong?