I'm a 20 year old male and I have an unexplained pain in my abdomen. It feels like a tearing, stabbing pain, but it only happens when I twist a certain way or lean back or bend all the way down or when I run (basically only when I'm moving). The pain kinda feels like when it happens, my abdominal muscles contract. There is no visible swelling or bruising. I've been to my physician who referred me to a GI, where I had blood tests done. I was negative for H Pylori. I also had an abdominal ultrasound that came back negative. Any idea what it could be? Sometimes the pain is localized to the left side of the abdomen and sometimes I feel it across my entire abdomen. Pain is worse at night when I twist and turn in bed, and for some reason when I lean on something with my weight on my arms and then I stand up straight, there is a strong pain in my abdomen.