since 2 months I have been having some GI symptoms. Everything started with some nausea (no vomiting) that initially went away, but came back few days later. I had some other symptoms such as excessive gas and gas related stomach pains. After roughly a month, I visited a doctor here in Japan (on a business trip here for 3 months), had a complete blood-work done including tests for liver and pancreatic functions and some cancer markers as well as an occult bleeding stool test. Everything was fine so I was given 30mg omeprazole to take every morning after breakfast for 6 weeks. The doctor things IBS or reflux. After some 3-4 days, all symptoms cleared, but another week later the intermittent, very light nausea came back. It is usually the worst in the morning, or in moments when I can stop my activity and sit down in the evening. I am working as a mountain guide so my days are mostly in the field and very busy, but once I have a moment to stop, it often re-appears.
I'm pretty good at googling scary things, so mostly worried about stomach or pancreas cancer... Do you think I should seek some further investigation right away, or rather wait to finish my omeprazole regimen and try to calm down?