After defecating hard stools I drank water and eventually defecated more hard, then normal and loose stools. Now I have gas. Normal?

Not worrisome. Perhaps you had a stool plug which has now passed. A "good news" is that you have not described bleeding per rectum. Changes in bowel pattern are however a "red flag" to doctors. Depending upon what is a "normal" stooling for you, please discuss your recent bowel irregularity with your doctor who can put it in perspective with the rest of your rx & medical history (with which we are un-aware).