DD1 was simaler. Took her to a paed and he ran some blood tests. At this stage we have put it down to anxiety. We notice when she is anxious about something that she gets tummy aches and sometimes throws ups. Her teacher often said that she would complain of a sore tummy if they were about to do something she was unsure of. She has improved (which is great), but is likely to suffer IBS as an adult (they are connected). Looking back now, I was the same as a kid and even now, my nerves affect my tummy. Amazing how emotions can affect us.