I've been feeling a pain in the left side of my navel ...

I have been feeling a pain for some months, not strong but uncomfortable on the left side of the navel, I do not drink much water, there are days I drink 2 liters of water and the day after it does not hurt, but when I do not drink water, when I do massage on where it hurts, loose gases. I wonder what he might be or what doctor he should look for. Thank you very much in advance!
Expert answer:

It may be a problem of the urinary tract, but it is more likely that it is intestinal, you can look for a general practitioner himself, he will start your investigation and treatment and if you need to refer you to another specialist.