Altho not officially diagnosed I likely had OAB or maybe just a small bladder when I was very young. Always needed to use the bathroom sooner than others, and could not wait as long as others when I did need to go, even when restricting water intake. When I was 10 I had my appendix removed (an uncomplicated procedure unlike the earlier poster) and it seemed to get worse after that, so it probably had some affect on an enervated area manifesting itself with urgency. Also, the stress and anxiety this added to my life caused.... more stress and anxiety which made it all worse.