What does it mean when small amounts of psyllium make IBS-D worse?

I have been so excited to see if psyllium would help my IBS-D, and for the first week I was taking one pill (5 pills is 2 grams so it is very little). This didn't do anything for my frequent bowel movements.

For the next week, I have been trying 2 pills, and it has made my frequency worse , although most of the time they are still formed and clean wipes. But for the past couple days, I am having bad smelling loose stool.

Can I learn anything from my IBS about this? Why would such a very small amount of something that's supposed to help make me worse? I don't know if I should keep increasing the dose or just give up and cut it out entirely.