I pass Guifenisin pills in my stool all the time

I take Guifenisin tabs to reduce mucous buildup in my system. The pills are pea green and they are about the size of a Tylenol caplet.

When I first started looking at my poo a few months ago, after starting P&B shakes and Liver cleanse....I saw a green looking thing floating that freaked me out...I also fished it out and broke it in half....it was the Guifenisin tab that I took earlier.

Since then I notice those tabs in my poo all the time...I don't know why they don't dissolve.