What happens, very basically, is this ... when you ride long distances you are generally not as well hydrated as you should be. In your case, it is possible you weren't as well hydrated as you should have been each of those days.
Because you are not well hydrated over an extended period of time, your body goes into preservation mode. Any liquid it gets, it tries to store in your cells. You may notice this change by symptoms such as reduced sweating, and limited, dark urine.
When you finish your ride, you're thirsty, and the natural reaction is to drink lots, and lots, and lots to try to make up for your lack of hydration during the ride. But meanwhile, your body is still in preservation mode, and so for a while, the increased quantity of liquid you are drinking goes into your cells ... and you bloat, and your ankles swell (I've seen my ankles puff up to nearly twice their size).
A few days later, your body realizes that all is back to normal again, and so it releases its store of liquid, and you end up peeing like crazy for a few days.
Ideally, to prevent this from happening, we should be consuming something in the neighborhood of the 8 glasses a day we've heard about since we were kids ... and when we're on a bicycle, the recommendation is about one 750 ml bottle of water and/or sports drink every 1 to 1.5 hours. But it is really hard to keep that up over a long ride, and sometimes over a tour as well.