I Have A Bulge In The Lower Right Abdominal Area

I have a bulge in the lower right abdominal area across from the navel region. It feels like a muscle to me (if I had any muscle in my fatty abdominal region). It is firm when standing, but not as obvious when laying down. I was told ny 4 physicians it is not a hernia. I had a CT scan nd nothing showed up. I DO have an umbilical hernia, however, but this appears unrelated...or is it I also had a complket hysterectomy a year ago.