Everyone recovers differently. So, you may be ready to go back --- I don't have a j pouch, so I'm not speaking from experience. But I am sure others will be along to give you their 2 cents worth.
You might just want to check into who your contacts at the Univ are IF you need to cancel for the semester. At least you will have the research done now, phone numbers in hand and deadline information for full refunds. As far as refunds go, a medical excuse - providing your doctor will give you one - may override all the deadlines for you. Check into that as well. Just my suggestions - I worked at a University and they are pretty sympathetic to illness related withdrawals from school.
Diagnosed with CD in 1979, many resections and meds
Perm Ileostomy July 1984 at Cleveland Clinic
Disease free since surgery