Constipation and Fiber One?

What are y’all doing for constipation? I eat primarily fruits and veggies, I avoid processed foods and sugar. I’m still going but it’s not fun lol, and now I have hemorrhoids of course 🤦🏼‍♀️. I’ve added Colace but I’m hoping to avoid a laxative. Have y’all used Fiber One products and did they help? My husband just bought Fiber One cereal and some of the chewy bars for me to try. I drink between 100-120oz of water a day religiously. I eat a ton of fiber daily so I feel like this shouldn’t be an issue but apparently it is 😠.