You probably glance before you flush. Most of us only notice when something looks different, and then quickly wonder whether it means anything.
For most changes the answer is no, but a handful of colors are worth paying attention to.
Normal stool is brown because of bile, a yellow-green fluid the liver makes to help break down fats.
According to the Cleveland Clinic, the pigment bilirubin in bile is what gives stool its brown color.
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When bile flow drops, when there is bleeding somewhere in the gut, or when food moves faster or slower than usual, the color shifts. Most single changes are harmless and tied to what you ate. A few patterns deserve prompter attention.
Green stool usually traces back to the plate
Green is the color of bile before gut bacteria finish breaking it down into brown pigments. When food moves through the intestines quickly, the pigment does not have time to change.
According to UnityPoint Health, leafy greens, iron supplements, antibiotics and stomach bugs are common reasons. Short bouts are usually benign.
If green stool runs with ongoing diarrhea or stomach pain, call your doctor.
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Yellow stool may mean fat is not being absorbed
Yellow, greasy stool that floats or has a strong odor suggests the gut is not pulling fat out of food. UnityPoint Health notes this can point to a problem with the pancreas or the small intestine.
If yellow stool lasts more than a couple of days, bring it to your doctor.
Pale or clay stool points to blocked bile flow
Pale, gray or clay-colored stool is the shift that most often signals the liver or bile system.
The Cleveland Clinic calls the biliary system, meaning the gallbladder, liver and bile ducts, the most common place to look.
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Gallstones, inflammation of the liver from viral hepatitis, scarring of the liver (cirrhosis) and tumors in the pancreas or bile ducts can all slow or block bile.
Medical News Today adds that many drugs can harm the liver and alter stool color.
Barium used in digestive X-rays and antacids that contain aluminum can also give stool a pale look for a day or two.
Occasional pale stool is often harmless. Pale stool that lasts more than a few days needs a medical evaluation.
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Bright red stool suggests bleeding lower down
Bright red usually means fresh blood from the lower gut. UnityPoint Health lists hemorrhoids as the most common cause, but inflammatory bowel disease, diverticulitis and polyps can also be behind it.
Any bright red bleeding is worth telling your doctor about, especially if it keeps happening or comes with pain, dizziness or a change in your usual bowel pattern.
Black and tarry stool may signal upper GI bleeding
Black, sticky stool that looks like tar is different from stool darkened by iron pills or black licorice. It usually means blood has been digested on its way through the gut.
The National Institute of Diabetes and Digestive and Kidney Diseases lists black or tarry stool as a warning sign of acute GI bleeding that needs immediate medical attention.
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Common upstream sources include peptic ulcers in the stomach or small intestine and gastritis, which is inflammation of the stomach lining.
Both can be set off by the bacterium H. pylori, long-term use of painkillers like ibuprofen or naproxen, blood thinners and heavy alcohol use.
When a color change needs same-day attention
A single shift tied to a meal, a supplement or a short stomach bug rarely means something serious. The pattern to watch is a color change that lasts, or one that comes with other symptoms.
The Cleveland Clinic says to seek urgent care for pale stool combined with yellow skin or eyes and dark urine, a trio that suggests bile is not reaching the gut.
Black tarry stool, repeated bright red bleeding, or any color change paired with dizziness, fast heart rate or confusion warrants a same-day call to a doctor or a trip to the emergency room.
This article is made and published by Ida-Marie Palm Varbæk, who may have used AI in the preparation.