5yr old complains of tummy ache to avoid activities

[BelleCurve]

DS 5 complains of tummy ache, feeling unwell for new activities. He creates a fuss for new situations eg swimming lesson, holiday club.

I've tried tactics to manage his anxiety and he has a great time when he gets into something. In many ways he is quite confident, self assured. Is there anything I can try to stop this? Today he is refusing point blank to go swimming, yet he loved it last week. Yesterday was a fuss going to school because they had PE.

I don't force him if it is something optional, but he has to go to school.

Do you prepare him for what's coming, e.g. "DS we are going swimming in half an hour, when the long arm on the clock gets to the 3"? Have you tried a timetable, maybe with pics of everything he does (e.g. get dressed, eat breakfast, bath, swim, go to school)?

Yes we always talk through the plans. I think that sometimes makes it worse, as in gives him more time to work himself into a state.

Ok, could you then try the opposite? Just let him do whatever he is doing and then go "Come DS, let's go swimming."?