Not a wine drinker, and had three glasses of Shiraz (red) wine last night. Have been constipated off and on for a while now, and have been taking ground flax seed daily which helps, but sometimes I dont drink enough water so I flop back to being clogged

anyway...3 glasses of red wine last night. Wake up this morning, have a normal BM, normal chocolate brown, and then around 11 another, but this one is BLACK. Looks like a normal stool shape/size wise, but BLACK

about 3 hours later, another smaller BM, still black.

Ive been having cramping, clogging, some narrow some BIG stools...all variable over some time, but never black

seems to have been triggered by the wine that I may have overdone?

Has anyone ever experienced this before?

Will call a gastro doc tomorrow...