Usually I gain about 8 pounds on carb up nights, and all throughout the night, I piss every 30 minutes - and in 24 hours, I'm back to my normal weight...
I have the same problem...and it seems I hold onto the water for awhile as well. The only problem I see it causing is not being able to gauge my progress. I'm a pound more this week than last, after my refeed......I consumed more carbs this week as well.