Chocolate can make you poop if you eat enough of it because whatever you eat can make you eventually poop when your body removes the waste it no longer needs after processing the foods you eat including the chocolate.
I find that just eating a few pieces of chocolate doesn't make me poop soon after but if I eat say 3 chocolate candy bars then I usually need to poop 3 to 4 hours after eating the chocolate bars.
Just eating a bit of chocolate though doesn't help with constipation but you will eventually poop after eating enough chocolate.
Plus chocolate is good for your health as well when eating it in moderation.