Julie - I agree with Pat - maybe the doctors should check the volume the bladder can hold. When I was cathing every two hours, and only two weeks into it, I was sometimes emptying 3-400 and at three weeks discovered I could hold 500. I wonder if you are drinking enough. If you are drinking plenty, then maybe you are not emptying completely. I remember the spasms...for me it was almost like a cramping; I would find myself having to empty earlier than I had expected and I would be fuller than I thought.
I kept a spiral notebook journal for the first two months...on each page I had four columns...the date and hour, the amount of liquid I had consumed during the previous two hours, then listed the amount of urine I emptied, and comments where I noted if there was leaking, irritation or mucus. That way I could keep track of my progress and better determine if I was putting out as much as I was taking in.
In my early entries I had lots of notes on leaking, some irritation, and many comments on mucus. I was able to extend the cathing to three hours after the first month and during the second month, I was able to move to four. We're all different and progress at different rates. It takes time and patience. Stay in touch and keep the faith. I hope and pray you don't have a hernia...doesn't sound like it to me. Hugs,