diarrhea and cramping ,discomfort after taking food..all leads to a terrible experience . as far as your reports you have got upper g.i endoscopy ..you may also require a colonoscopy and study of stool. dietary changes are also important other than medications.fiber rich diet avoid fats. if you are smoking or having alcohol intake ..quit . also keep a note on your weight, blood or mucus in stools. take syr sucral  20 ml ,15-20 mins before food three times a day..that might help alleviate your gerd and esophagitis  in addition to your current medication