You need to find out why. Have you asked him if anything is going on at school that’s bothering him? I’d sit down and try talk to him about it.

Try and find the reason he’s avoiding school and attempt to solve the real issue.

As below, ask the needed questions.
Be gentle about it as if it’s bullying then it might be something he will try and hide so just let him know that he is able to talk to you about whatever is going on in a safe space.

The question is, WHY is he doing this?

My brother did this as a child. He would also get on and then convince the bus driver he was sick and get off and walk back home. He was being bullied. Something must be going on and that you have to get to the bottom of.

I think you need to ask him whats going on, there has to be a reason why he doesn’t want to go.

My mother did what BellaB suggests. No tv, books, pets or entertainment. No lying on the lounge – stay in bed unless going to the toilet. No food other than bland foods – water, bread and butter, fruit. This lasted until the next morning – so no playing with siblings after school or night time tv. We never wanted to stay home unless extremely sick.
Talking about what might be causing the issue would be good, and getting the teacher and school counsellor involved.

He may just be bored with school or there may be something deeper going on. Try and get him to open up to you about the reason behind it and if he wont open up to you then I would definitely recommend getting him to talk to someone else.

Find out why.. might be something happening at school, maybe a teacher has left or bullying is happening

Definitely try to find out what is behind this change in behaviour. What’s occurred to make going to school feel like such a huge threat.

Two things. (A) make being at home insanely boring. If he’s “sick”, make him stay in bed. No TV, no other screens, not even a book. And (B) try to work out if there’s a problem at school.

I would like to find out want is behind this. Why does he not want to go to school ? Is it too hard ? Has something happened ? Is he bullied ? I would probably request a chat with the teacher as well