My wife had the same problem. The Doc had her eat radioactive pellets to track their movement through her intestinal tract via X-rays.
Turns out she had what they call a "dead" colon that was unable to perform the constriction necessary to push waste toward and out of her abdominal tract.
We tried drug therapy as a solution to no avail and eventually she had to have 90% of her colon removed. She now has a 6 inch section of functional colon with few side effects.
The doctor provided us with a post-op picture of him in full operation scrubs proudly holding the removed section of diseased colon like it was a large snake he had captured in my wife's bowels. I was amazed at the size and volume of tissue removed from my wife's body.
To fill the void left by the dead colon they installed/implanted a gortex sponge to support her remaining intestinal tract. Over time scar tissue developed and attached the sponge to the back of her abdominal wall along her spine. Imagine cleaning a fish, after the guts are removed you can see exposed backbone. This is where the scar tissue developed that created discomfort to the point of pain management via drug therapy. Although operable, it is basically a reverse of the entire process that my wife is not willing to do.
Start to finish we're in for about $750K. Insurance covered 80%. I guess we were lucky? to only lose $150k
That whole dead colon thing was a real pain in the a$$ and I wouldn't worry much if I was you...