I don't know about the thirst but for constipation you also need a clean liver to make enough bile, so the food in the small intestines will digest the food better.
So my only suggestion is to add liverflushing every 2-3 weeks. I like Oxypowder too, but since I have been on WD and have been putting 35% foodgrade H202 in my drinking water I have not used it. I always have some bottles in the house since I go through stages of compulsive eating. You can use less so you don''t get buttpee.
In general I am pretty clean I would think, done 48 flushes in more than 3 years plus the oxy off and on.