How long does it take for omeprazole to work, and what are the implictions of taking it?
Many people report that they get relief from one pill. But, in general it can a few days to see if you are going to get relief and a full two weeks to see the optimal effect. This is because it can take a while for any irritation to heal.
In the short term there are no known concerns about taking Proton Pump Inhibitors other than the side effects listed in the brochure. On the other hand, more and more research is coming out demonstrating long term side effects such as increased risk of fracture, low blood magnesium and a rebound effect when you go off of them. These are all concerns to talk to your doctor about should you need PPIs long term. You are your doctor will have to discuss the benefits vs. risks in your specific case.
Here are some links on reflux that you might find useful:
Heartburn Trigger Foods
7 Symptoms of Acid Reflux
Understanding Acid Reflux: A Doctor Q&A