Alex missed more than 8 weeks of school during the "year of discovery/diagnoses" - that was 7th grade. He missed the entire 3rd and 4th quarters and end up finishing the year through the County's Home & Hospital Program. (HHP)
He started 8th grade with the intention going full-time back to school. However, by the middle of the 2nd quarter he had already missed more than 15 days - it was our pediatrician (who is in our County) not the GI (who we go into the city to see) who said, "Why stress about this, let's home school him." And he filled out the paper work to put him back on the HHP.
When we went in over the Summer he asked Alex what he wanted to do for 9th grade - Alex asked if he could continue on the HHP and his doc said absolutely - and to let him know IF and when he wanted to return to the classroom. He (the pediatrician) sees a *real* connection between stress and flare ups. Alex is growing, eating, and doing great - he see no reason to jeopardize a good thing - in his (the docs) opinion - If it's not broke, why fix it.
Alex is taking all honors classes, is carrying a 4.0 GPA and studies at HIS pace doing any where between 2 to 3 subjects per day. A teacher comes in at least twice a week to help him with core subjects and to mentor him (he shows up at Alex' hockey games and has truly taken a interest in his success - it's awesome!!).
There often seems a big push to keep the kids in school - but when and where possible (and by ensuring other activities are available) home-schooling is really great.
Through our Church we have a program we call "Seminary" - it is a Bible Study Class for high school students. In our area, the kids go in the morning before regular school starts (6 to 7 am) - Alex participates in that (about 32 kids there), he's involved with Scouts and our young men's program at Church (about 20 boys there), he plays ice hockey, goes to church dances, and is a baseball umpire for our local youth organization - so plenty of time for "socialization" that people fear that kids who are homeschool miss out on.
(Always feel like I'm on a soap box about it - but the questions I get often show a fear to do it - my feelings "try it - you'll love it.")
Good luck!