Poop that’s blue, or any color that’s not brown, including red — which can sometimes indicate blood in your stool — may be jarring at first. But because it’s nearly always related to what you’ve consumed, it’s not likely to prompt a doctor visit, says Ashkan Farhadi, MD, a gastroenterologist at MemorialCare Orange Coast Medical Center in Fountain Valley, California.
But if the blue tinge (or any other abnormal color) persists after you’ve changed what you eat, and you’re not taking medications known to cause it, he suggests a visit to your doctor.
Changes in your bowel movements that require immediate attention include:
- Blood in your stool
- Poop that looks deep red, maroon, black, or tarry
- Pale, white, or clay-colored stools
- Persistent diarrhea or constipation that lasts longer than two weeks
- Nausea and vomiting that occur along with constipation and abdominal pain
“Basically, it’s helpful to know what your stool looks like when you’re healthy and there are no issues, so you know your baseline,” says Dr. Farhadi. “That way, you can detect any issues, such as ongoing diarrhea or very loose stools, or color changes that don’t resolve with diet changes.”
Particularly if you see blood or blackened stools — which can be an indication of upper digestive tract bleeding — that should be a cue to contact a health professional, he says.
That doesn’t mean it’s automatically an emergency, since it could be related to foods, medications, or supplements such as iron, which can darken stools.
But it’s best to get checked to make sure there isn’t a more serious issue, he says.
