metamucil absorbs the water in the colon, it bulks the stool and makes it easier to pass so that you are not straining causing hemmeroids and even fissures.
It also cleans the walls of the colon.
It is a good fibre supplement to take but not the sugar free one.
Many of us here take metamucil fibre. I take it every night before bed.
Probiotics depending on the brand add good bacteria, help with diahrea, firm stools, and improve overall health.
Bio-k plus is a great probiotic its found in the refridgerator of the health food store and some grocers now carry it. It has helped me out of the worst of my flares years ago but I still take it daily. You need the good bacteria in the colon otherwise the bad take over and cause problems. I find it best to take on an empty stomach.
I see you are taking fish oils they are great but for some they cause loose stools.