Look i've just dug this out of a web site, its a bit of info on your drugs,
Minor lansoprazole side effects
Some of the lansoprazole side effects include stomach pain, irregularity, diarrhea, headache, nausea and dizziness. While most of these lansoprazole side effects are considered to be minor if you have any of these lansoprazole side effects for more than a few days, you should contact your doctor immediately.