5 whole days off school and get an attendance letter??

[Walkingalot]

I've had a letter from school stating that my DS's attendance is now at 95%. He's had 5 whole days off school so far. The 1st recorded date is 9/21. The letter states that it's the equivalent of two weeks away from school. Sorry, I just don't get it. What am I missing here. The letter goes onto say that they'll need medical evidence. The reasons for absence is usually that he's been sick that morning. His suffers from anxiety (ASD). How on earth am I meant to get medical evidence for that?
I do understand the importance of attendance and I send him in if he has a cold or I sense he's just making excuses. I really don't understand how they've got their figures.

Update - I rang my DS's GP and the receptionist advised me to email them explaining the situation. I got the letter yesterday. They wrote confirming his diagnosis and all the other issues that come with it including anxiety induced sickness. Job done. I'm so relieved as the letter will be useful for his DLA renewal too.

@carltonscroop

Well if they are saying 20 sessions, or 10 days, then they are factually incorrect and you should write to then to set out the correct version.

I would also remind them that NHS do not issues sick notes for illnesses below 5 days and you have no means to provide any 'evidence' other than standard self-certification for short absences.

If the school wishes, at their expense, to provide a private GP appointment on the day of next illness, you will of course do everything to facilitate that

Do this, it shows engagement if the school ever decide to take it further (unlikely given his diagnosis). After that, try to forget about it and don't feel bullied to send him in if you feel he isn't up to it that day.