Sorry I don't have an answer, but I was just about to ask people about the same topic. About 6 months after surgery for colon cancer (and ending up with a permanent colostomy) I was awake all night with severe crampy pains going right through my middle. Better in the morning, but my doc said it was not a blockage or anything to do with my operation... she said it was probably muscular, and that made sense at the time because I had been rooting under the bed for a lost book and thought I felt something twist!
However, since then I have experienced similar crampy spasms every few weeks - sometimes lasting only a few hours, sometimes two or three days. During this time my bag is empty, and when things move again it is pretty slow and undramatic. The next time I saw my doctor she said that the gut is sensitive and with the type of inteference I've had with surgery it will be prone to going into spasms. She prescribed Buscopan to relax the muscles whenever it happens.
I don't find that the Buscopan helps very much....... Just wondering, do others experience these pains regularly - and what helps in the way of drugs or exersize?
By the way, I find the pain slightly eased if I lie on my right side in bed. Don't know why.