Hi Adriana, it's not shy bowel, but it sounds as debilitating and life limiting as shy bowel.

Have a look at the 'to coffee or not to coffee?' thread. Especially the posts by 'Shy + Urgent'. They've been experimenting with glycerol suppositories to have a 'clear out' before going out which leaves them less anxious and more able to enjoy their time out. Might be worth trying it out?