I remember my now 24 yr old son in his early secondary school days complaining of tummy aches on many school days. I decided he was trying to skive off for whatever reason, and one day I decided to call his bluff. I marched him down to our GP and told the GP he was complaining of tummy ache and was expecting the GP to prove nothing was seriously wrong. The GP told him to lie on the couch and had a feel of his tummy then declared, "oh my goodness, come and feel this" - and I could indeed then feel something quite hard and nasty and it turned out my son had a severe case of irritable bowel syndrome. I have never been quite so cynical since, and my now 14 year old daughter probably gets away with a few more days off than her big brother did!