I sure battle with these issues too. Since increasing my Seroguel and Benzo I now struggle to stay regular. What's helped is psyllium husk which the the main water soluble fiber in many of the OTC like Citrucel. I add it to my morning protein shake and it has no sugar or sugar substitutes so it's much healthier. Come is a gel cap form too that you can drink with a glass of water. Keep eating lots of greens and you should be regular in no time.
Good luck with the going!