I tried All-bran cereal from Kellogg’s a few days ago, and it dropped my frequency significantly. I ate a 1.5 cup bowl with milk, and I heated the cereal in the microwave for a minute, as I usually do with harder cereals.
However, I read here on this forum that all-bran gave some pouchers terrible obstruction! So be careful! I guess I did not have issues because I heated it like instant oatmeal, and it was easy to chew.
One member said that their Dr recommended only 1/3 cup a day. So, I ate 1/3 cup today again heated, it did not make a huge difference in frequency. You might try different amounts, and methods with/without milk, heated/cold, but be careful not to get an obstruction! Chew it very well.
After my experience with all-bran cereal, I searched “bran” on this website, and saw a member writing about “Smart bran” cereal. I will see how that one will work. It has multiple bran types from different sources.
There are many fiber supplements out there, for both water soluble and insoluble forms, like Metamucil or Citrucel. I don’t like eating fiber in a supplement form, it feels like a duty. So I am trying to find something that is a real meal and includes what I need. I hope I can make it work with bran cereals, as they have both water insoluble and soluble fiber, and I like the taste. They can also be added in other baked goods. I hope this helps.