Is there an alternative to gallbladder removal?

My husband, age 42,  has suffered with chronic pain  just below his ribcage on the left side for 2 years.  The pain radiates to his back as well.  Gravity seems to make the pain start as well as eating or perhaps a combination of the two.   If he lays down for a while the pain will go away.  He has had several tests to figure out what the pain is.  He has no gall stones, but a recent HIDA scan found that his ejection rate is only 6%.  His doctor has recommended surgical removal of his gallbladder.  He is very reluctant to have the surgery and is wondering if there might be other options.  
One concern is that he takes 40 mg of Quinapril to treat his high blood pressure.  His doctor thinks the high blood pressure is hereditary and that even if he exercised, cut back on the salt, controlled his diet etc, that he would still have to be medicated.  However while he is a fairly active person he hasn't tried regularly exercising or committing himself to a very healthy lifestyle to see if he can get off of the medication.  He is not overweight.  WHen he was regulary lifting weights as a younger person, his blood pressure was still on the high side, but not high enough to medicate.  He is wondering if the Quinapril could be the cause of the biliary dyskinesia and if he stopped taking Quinapril, would the gall bladder recover to a normal status?  I have been unable to find any information about a connection between Quinapril and this disorder.
IF the Quinapril is completely unrelated, can biliary dyskinesia be treated with an alternative to surgical removal of the gall bladder?
Can the gallbladder ever return to normal again under any circumstances?
What causes biliary dyskinesia?  why does the gall bladder work fine one day and then stop working the next?  Could biliary dyskinesia possibly be a symptom of some other problem?
thanks for any thoughts or pointers in the right direction.