Stayce5, I am 7 days post op and it is still impossible for me to drink 2 ounces every 15 minutes, my belly hurts if i drink 2 ounces at a time and I have to take a break for about 30-40 mins. I try to do about one ounce every 15-20 mins (Not regularly) I am at present doing 35-40 ounces a day. I spoke to my bariatric centre about this and they told me that although it is less, it is not too bad and I have to slowly increase it as much as I can tolerate.
So dont worry about failing, you will get there.