I have hypothyroidism too, and had a total hysterectomy 14 years ago with tubes and ovaries removed too as ovaries are very very large cysts. My bowel worked great with water, fiber and exercise until about 2 yrs ago...started to have very strong urges to go and better be by a bathroom! Almost like a "dumping syndrome" with
BMs for a good 8 to 10 months. Now I have gone the other way...no urges to go unless I take something. About 2 weeks ago I quit all fiber supplements and stool softeners, etc, and did low fiber diet. That helped a lot for 2 weeks. But now back to no urges to go. I'm sorry we share this plight! I'm having colonoscopy in a couple of weeks to see what is going on. But right now not sure what is happening, like you.