I was constipated for a week when I first arrived, HOWEVER I learned the key to going #2 was privacy. so once I was alone and got settled in to where I was staying, everything was fine.
am I cured? absolutely not. I couldn't go unless I was alone and I also have rituals to help me go (like having tea and reading)my body is basically trained to only relax at certain times.
but overall it did not affect my trip badly (except for the first week) and if anyone is fretting about traveling or not bothering to go on holidays because of shy bowel,try not to worry about it!
good luck guys!