A little more info for you
Jack's absences are excused, I don't have to have a doctor signature on each one but if we are getting to the 9 day/semester limit of our school district I just call the GI and he writes up that yes, he has been having issues directly related to his disease.
Also if extended absence we can have the homebound teacher come out and teach, she basically keeps him up to date, we also have in ours a permanent bathroom pass, he is free to get up and use the restroom at anytime without penalty and does not have to ask permission. A lot of his teachers have offered him a seat next to the door if he would like it. He is allowed to go lay in the nurses office at any time. He is allowed to have snacks in class. He is allowed extended time to make up work after an absence. I believe standard is 3 days he has 10 per 504 but a lot of his teachers do not hold him to a time limit as he is also an A-B student and they know he will get it done.
He has just missed several days recently and went back to school yesterday and called me when he came home saying he was tired but he had a lot of homework, he ended up taking a nap and was still able to complete some of his missing homework. I will sometimes get an email from the teacher just telling me what is missing so we do not end up missing something.
The 504 meeting is generally held with her teachers, the nurse, counselor. Jack always attends along with us and most have been very gracious and ask if there is anything additional that would help him out.