I Have Had A Gastric-By-Pass In 1989, It Is Still

I have had a Gastric-By-Pass in 1989, it is still working. But in 2011 I had a bout of bleeding ulcers, the Gastroloigist who treated me put me on Prilosec 40 mg. once a day. He said that ulcers just below the stomach pouch was very common in Gastric-By-Pass patients. I am 69 years, but after a very stressful time, 9my Husband was told he had Melanomia had spread to his upper lungs); my ulcers started to act up and bleed again. New Doctor, tells me no Prilosec, instead said I needed to take Pantoprazole 40mg. (Nexium). With this new medicine I have pain in my upper intestines 30 to 45 minutes after eating. Sometimes I vomit uncontrolabily. Should I ask my Primary Doctor to put me back on the Prilosec?