Mine started when I was young enough to still be in a crib. I remember that I was crying and then started to V in my crib and I couldn't climb out I just sat there and cried and my mother didn't come help me for what seemed like hours to me. I asked her about this to see if it was a bad dream but she confirmed finding me screaming in my crib sitting in V when I was about 2 years old. Having chronic IBS has never helped things either.