You said you have been on
prilosec for 15 yrs and also take metforminl. The info I read about
prilosec suggested that it should only be taken short term. That it wasn't for long term use. Some possible side effects from Prilosec were: headache, abdominal pain, nausea, diarrhea, vomiting and gas. Also, with the metformin...under the "less serious" side effects these were listed: mild nausea, vomiting, diarrhea, gas and stomach pain.