You sure might have had untreated pouchitis, and Canasa doesn’t really treat that. That probably doesn’t explain the nausea and vomiting, but people occasionally report feeling pretty sick with acute pouchitis. Your fatigue might be a side effect from one of the antibiotics, if it’s not from whatever made you acutely ill. I usually prefer trying one antibiotic, since that reduces the side effect risk (and is often sufficient). 1-2 BMs is low for most J-pouchers - but: do you feel good, or do you feel backed up?