LBH, something similar happened to me about three years ago. I was driving my dad to the eye doctor and I started to get the worst cramps I have ever felt in my entire life. We got home, I took myself to the doctor's office, and the doc told me she couldn't find out what was wrong. She said there was "obviously some sort of infection", and told me to go to the ER immediately. So of course I was terrified. My mom took me to the ER, we sat there until almost 3 in the morning, they did an ultrasound and a bunch of blood tests, and couldn't find anything wrong. The first thing they checked for was the poo problem, but that wasn't it.
Anyway.... they never did figure out what was wrong. But they still charged me a grand for the ER visit and ultrasound. And not only that, I had to fix my car afterward, because as I was leaving my house to go to the Doc's office, I ran into a tree in my driveway.
Hope the meds start working soon.