Very bloated after drinking moderately for few days. had low back pain and then urinated excessively for a day and felt better. what can cause this?

See answer: Most common cause of abdominal bloating is swallowed air which often occurs with eating too fast and drinking a lot of fluids especially if fluids are carbonated or contain artificial sweetners. The body may retain much of that fluid for a short time (especially if diet contained an excess of sodium) and than get rid of it in a very short time (diuresis) which explains the frequent urination.