Stool Colors - What's Normal?

Going number two is not exactly a dinner party conversation, but it’s one you might need to have with your Gastroenterologist if you experience constant irregularity or if you have questions or concerns. So let’s cut the *ahem* and talk about it –  it’s a normal part of our digestive process and depending on your diet, your stool can vary in size, smell, and color. A healthy stool is typically brown, but don’t be surprised if you come across a rainbow of colors every once in a while. The color of stool changes based on the foods we eat and how much bile (fluid our liver produces to digest fat) is in our feces. So when is “colorful” stool a result of diet and when is it a cause for concern?

Green Stool

Green stool is typically normal. In some cases, green leafy vegetables, iron supplements, and green food coloring might be the cause. In other cases, green stool might mean that your meal moved through the large intestine too quickly, and the bile didn’t have enough time to break down fat. Often when this happens, you might experience some diarrhea. 

Yellow Stool

Yellow stool is also quite common, especially in babies. However, if your stool is consistently yellow, greasy, and foul-smelling, it may be due to excess fat in your diet, which can be caused by conditions that disrupt the intestinal lining.  In some cases, it may point to signs of liver, gallbladder, or pancreas disorders. Serious conditions may show symptoms such as nausea, headaches, constipation, and bloating.

Black or Dark Stool

Possible dietary causes of black stool include iron and activated charcoal supplements, dark foods such as black licorice, black stout, and bismuth medications. Serious symptoms of black stool might signal bleeding in the upper digestive tract, such as the stomach or esophagus. If black and dark stool is not a result of diet or supplements, consult your Gastroenterologist to rule out possible disorders.

Red Stool

Seeing red in your toilet might be alarming, but before you panic, let’s consider some of the foods that might be turning your stool red. Foods such as beets, cranberries, red food coloring, ice pops, and red licorice will likely affect the color of your stool and are typically not a cause for concern. However, if you experience red stool that is unrelated to your diet, it might be a warning sign for serious conditions. Blood in the stool can vary in color depending on where the bleeding is in the digestive tract. Stool that is bright red might point to signs of bleeding in the lower GI tract and may be due to conditions such as anal fissures, hemorrhoids, noncancerous tumors, diverticulitis, ulcerative colitis, and colon cancer. Blood from the upper GI tract will appear darker because it takes longer to move through the body. If you suspect the presence of blood in your stool, your Gastroenterologist might request a fecal occult blood test (FOBT), which can check stool samples for hidden blood that might otherwise go undetected.

Pale or Clay-Colored

Certain antidiarrheal drugs can sometimes cause your stool to look clay-colored or pale. In more severe cases, pale stool is the result of a lack of bile or an obstruction in the biliary system. Bile is produced in the liver, stored in the gallbladder, and excreted into the small intestine during digestion. If you regularly pass clay-colored stools, it may be a sign of a severe underlying illness. Some of the most common causes of pale stool include hepatitis, gallstones, tumors, and cirrhosis.

Consult your Gastroenterologist if you experience prolonged symptoms, changes in your bowel habits, or if you are generally concerned about your bowel movements.