How long does it take to notice a difference after starting a PPI like Prevacid? Does it take days or weeks to start to feel relief?

Usually a PPI starts inhibiting acid when you first start but it may take a week to notice any difference -- it just depends on your symptoms. But everyone is different and some PPIs work better than others. Prevacid did not work as well for my wife as Prilosec.
Also, I took Aciphex for a month one time and it never helped me.