It is very hard to answer your question as you did not mentioned what kind of surgeries was done and what is the histology diagnose.
The reason of persistent symptoms you are describing might be caused by some inflammatory intestine disease (Crohn`s disease for example), duodenum
narrowing (caused by chronic ulcers), or other reason of fading intestine obstruction like post-surgical adhesions.
CT of small intestines with contrast should find the place of narrowing. If its not possible to drink a lot of contrast at least an abdomen X-ray should be performed.