Can constipation cause bleeding out the vagina?

No. Constipation and straining on the toilet has nothing to do with vaginal bleeding. If you are having abnormal vaginal bleeding see your ob/gyn. If you are constipated try eating more fiber, drinking more water, being more active or taking metamucil, colace stool softner or gentle laxative e.g. Milk of magnesia (magnesium hydroxide). Good luck!
No but. Constipation will not cause vaginal bleeding but when you are pushing hard to poop that may push out blood that is already in the vagina and make it come out.