How To Treat Pain In Left Abdominal Area,gastritis And Passing Of Pale Stool?

I have been getting short lasting pain on my left side that seems a lot more accute today after having 4 beer last night. I generally feel a little sick to my stomach after having more then one beer the next day. Have a hungry feeling, lots of gas, fecal matter kind of 'splatters' and is lighter in color. Its hard to say this is anything but bad diet and bloating from poor eating, however there is a dull ache, and a jabbing pain in my left side that comes and goes. I have had this before when I have alcohol more regularly.