I didn't ate fruits for a year now, and have cut all carbs too for months. I only eat meat, eggs, fats like butter, non hydrogenated palm oil, lard,... and vegetables with herbs, Sea Salt ,... taking pancreatic enzymes, betaine HCL and magnesium as supplements.
I'm feeling much better, since I increased my fats intake, and my stools are finally (after months of severe constipation (often 1 week without going to the bathroom)) looking like they have to. No more mucus, etc.
Maybe you could try it.
I also drink a lot of goat milk kefir, and some water kefir, that help a lot for the constipation.
I drink the milk kefir (about a liter) before going to bed, and water kefir on a empty stomach in the morning.
The key, for me is a very low carb diet (only vegetables), high proteins and high fats, and choosing organic products, the most natural ones, without any additives, ...