Beets make your poop red. Does anything else do this? I’d like to know before I eat reddish snack food or something and have a heart attack from thinking I’ve got “internal issues”…
If there is something else that does this, it’s pretty uncommon.
Beet pigments:
And back to Wikipedia for Caryophyllales:
If the “internal issues” you’re thinking of are intestinal bleeding, that causes your poop to turn black, not red.
If you see red (and haven’t been eating beets or similar), it is most likely from hemmeroids.
Carotene will do it. A while back there was a young woman who ate basically nothing but carrots and yellow squash for a month to see if it would really turn her skin orange. It did, and unexpectedly her… waste… as well.
Drinking a bunch of grape Gatorade will yield an unpleasant purple surprise the next day.
Buzz Lightyear cereal (don’t ask–it was a sample in the mail) terrified my young son. It was purple output, but the input (flying saucers) were green.
Not necessarily. Colon cancer can cause red blood.
Black or “tary” stools are from upper GI (stomach and/or small intestine) blood that has been partially digested.
Red stools can be caused by tomato soup or juice, beets or red dye found in gelatin, Kool-Aid or cake recipes which cost $100,000.
The differential diagnosis for red stools (hematochezia) also includes hemmorhoids – but also anal fissure, angiodysplasia, colon cancer, Crohn’s disease and ulcerative colitis, etc. IN ELDERLY PEOPLE BLEEDING IS CANCER UNTIL PROVEN OTHERWISE.
Black, tarry stool (melena) is more often due to “upper GI bleeding” (above the ligament of Trietz of the duodenum) such as stomach or duodenal ulcer, esophageal bleeding, gastritis, etc. But there are lots of cases where the colour of blood is not reliable for determining the source of bleeding, so cuidado.
Polyps too.
Bob
I dropped a bright green one as a kid. It was from some sort of sugary drink. I was dead proud! 
Don’t worry, if your poop is red it’s most likely not ‘internal issues,’
it’s probably rectal bleeding.