constipation herbs

I found a good organic bulk herb website and want to make my own capsules.
Which herb is safest for constipation? Ive done LBB and have to take 10 a day! so i bought just cascara and 6 a day works for me. Is it safe to take cascara with no other herbs? I also read about Butternut, is this a better herb? Here is what I thought of making
Cascara
Butternut
Dandelion
Yellow dock

That addresses colon and liver. Any suggestions? Tweet