Vireo,
I'm sorry you're having to deal with this so soon after surgery.
The next time it happens, I would demand that they take an X-ray to see what's going on or schedule you for a small bowel follow through. It could be scar tissue that has grabbed a hold of your small intestine, which can be fixed with surgery. I know, because it happened to me.
Blockages are nothing to take lightly, because they can cause your intestine to perforate. I know, because that also happened to me. It was the most pain I have ever felt. If your current doctor won't help you, tell them that you will go to someone who will, because it's not right to go through this every day.
Cecilia