It's difficult because I have the rule of "evidence" before I keep them off.
That's usually D&V or temperature. (Limb hanging off doesn't count as dd2's is usually hanging off the side of her bed)
But my dc have totally different situations.
Dd1 never misses a day. Hasn't missed one since year 3 and she's in year 10 now. She will choose to go in rather than stay at home, she had toothache last year and still insisted on going in despite feeling terrible.
Dd2 gets migraines and has had a permanent tummy ache for now 15 months. The Dr can't find a cause, but says it is genuinely there. It may be linked to her anxiety, maybe not. I tend to, unless it's acute, send her in and the school will send her home if it's too bad late. She does have acute attacks when she can't go in, but the rest of the time she needs to continue otherwise she'll have 3 days off every week.
Ds is a little different in that he's got ear problems. Everything goes to his ears. He also, when an ear infection is coming, tends to not hear, get very oversensitive and generally be a pain at school. So I do have to be careful sending him in when not quite well.
For me there is a very quick thing with him in that he gets a distinctive smell when he's brewing one. So I keep him off, make a Dr appointment for the afternoon, and by lunch his temperature will be up, and he'll need antibiotics to stop his ear drum bursting by the next morning.
So I do behave differently. Dd2 I tend to send in, for two reasons, one being she's more likely to try it on, secondly she will go and say she's ill and the office know that she needs to come home. Ds will continue and just come out boiling and with a viral rash totally miserable.
If they're ill they also have to lie down in bed and no screens. Which tends to sort out any malingering.