hi there, heavy drinking for 4 years cannot be good for you and it is right for you to be concerned. The stomach ache can be explained by the gastritis
but the back pain
is something else. Kindlly get your serum amylase levels done the next time you have such pain. If it is elevated you will need to visit your physician as it signifies pancreatitis
and it is quite a serious condition. You could also get an abdominal ultrasound
done. Do try to cut down on your alcohol intake and do see to it that you consume lots of carbohydrate
and protein rich food along with it. Taking antacids may temporarily aleviate your pain and discomfort but in the long run you need to curb the habit. If you smoke as well then you need to cut down on that as well because it tends to aggravate the condition,. take care.