I only rarely drink soda, but when I do...I put in ice and stir the heck out of it to get rid of the bubbles.
I've never had a problem of needing to use the bathroom, the day of or the day after, but I would most likely have some discomfort from the bubbles that are left in the drink and how much I have.
I would never have diet or sugar-free...ever!
Use your common sense....eat your calories rather then drinking them...and pick as nutritious foods as you can. Since they don't agree with you...don't drink them. Fairly simple without all the reasons as to possibly why they disagree.
The other is...are you flaring at the time?
What meds are you on?
Are you drinking them with food or alone?
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