I wish I had any tips or tricks to help you ... I don´t go travelling anymore because of IBS/shy bowel. But if I was supposed to for a month- long trip I´d definitely learn as much as I can about the living arrangements. Will you be able to get a room with a private bathroom? I live in the dorms and I share a bathroom with just one roommate - one roommate is a bearable situation because there´s always times of the day when you´re alone in the room. But last year I shared a bathroom with 5 girls and it was hell - there was no privacy and no matter how much time I spent in the bathroom I just couldn´t go unless noone else was around ( which hardly ever happened).
So my advice is - try to arrange the accomodation now - definitely make a plan, get yourself either a single or a double room. You´ve mentioned you´re only able to have a BM at your place - I´ve got the same problem and I thought it would get easier being around people in the dorms all the time - but it didn´t. It was poor suffering - so with our condition the living situation is the most important thing, especially if you´re on a trip.
Hope you can figure things out and enjoy your trip without bowel problems