Although it can cause nausea and vomiting, it is not the churning upset stomach feeling that you get with a stomach flu. It is constant and in one location. Once the severity reaches a 7 or 8 it does not abate without strong pain medication. If it is caught before it gets that bad it can sometimes be handled with distraction techniques and more mild medications.
Yesterday, for example, Anne went through the afternoon and evening with low to moderate pain. That was a significant amount of time for her. Later in the night the pain increased, vomiting followed and she needed the strong stuff.