Causes Of Black, Green, Red, Orange, or Pale Stool

When Is The Color Of Your Stool Considered Abnormal?

Green Foods
Foods with strong colors can wind up turning stools an unusual color, such as black, green, or red. Thinking back about the foods eaten in the past few days may give an answer as to why a stool does not look typical. Image © fcafotodigital / E+ / Getty Images

What Is A Change In Bowel Habits?

Discovering that your stools are black, green, red, orange, or clay-colored can be a scary experience, especially if it has never happened to you before. When your bowel movements are out of the ordinary in color, consistency, or frequency, it is called a "change in bowel habits." Some common changes in bowel habits include having diarrhea, constipation, or an unusual coloration.

Most people experience one of these changes in their stool at some time or another in their lives, but typically it's only for a few days and the problem goes away on its own. In that case, it could be the end of the issue and a visit to the doctor isn't needed.

In most cases, an unusual stool color is harmless and can be attributed to a particular food or medication. However, it is important to note that this is not always the case. Changes in bowel habits that go on for a long period of time can be a serious matter and should always be checked out by a physician. Don't ignore problems with stools, especially when they are red or black without an obvious explanation, and don't put off seeing a doctor. It can be difficult to bring the problem up with a physician, but in the case of digestive problems, the sooner they are discovered, the greater the chances for a good outcome.

Strange Stools and IBD

Some people with inflammatory bowel disease (IBD), especially those who have had surgery to remove part or all of the large intestine may notice that they don't digest food in the same way as before the surgery.

This is not always a problem, it could be part of the "new normal" after having surgery. Sometimes (a lot of times!) foods with strong coloring (especially artificial coloring) can mean having stools that come out having similar colors. The color will stop when that food is digested and leaves the body.

Black Or Red Stool

Black or red stools that aren't caused by orange, purple, or red foods can indicate internal bleeding somewhere in the gastrointestinal tract. Stool that contains blood from the upper digestive tract is black, tarry, has a distinctive odor, and is known as melena. Stool that is red because it contains blood that typically comes from further down the digestive tract is called hematochezia. In the case of hematochezia, the blood may coat the stool, be mixed in with the stool, or even be passed by itself without any stool at all.

Potential causes of black stools include:

Potential causes of red stools include:

  • medical conditions causing bleeding (such as from hemorrhoids, anal fissures, or diverticular disease)
  • food containing artificial red coloring such as red gelatin or popsicles 
  • naturally red foods such as tomato juice or soup or large amounts beets

Pale Or Clay-Colored Stool

Potential causes of pale or clay stools include:

  • liver disease (such as hepatitis or obstruction of bile ducts)
  • antacids containing aluminum hydroxide
  • barium from a recent barium enema test

Green Stool

Green or black green stools could be caused by:

  • large amounts of green, leafy vegetables
  • green or purple artificial coloring (popsicles, Kool-Aid, gelatin)
  • iron supplements
  • infectious gastroenteritis (vomiting and diarrhea caused by a virus)
  • stool moving quickly through the digestive tract due to rapid bowel transit or decreased colonic transit time

Orange Stool

Potential causes of orange stools include:

  • some medications (such as beta-carotene and Rifampen)
  • foods high in beta-carotene: carrots, sweet potatoes, apricots, winter squash, pumpkin, cantaloupe, and mangoes
  • medical conditions such as a lack of bile or a blockage in a bile duct

A Word From Verywell

In most cases, a change in stool color is coming from something in the diet and is not something to worry about. Thinking back over the previous past few days and the food eaten or supplements taken might give some clues as to why the stool might have an unusual color. If a change in stool color cannot be explained for a dietary reason, goes on for a few days, or is accompanied by any other symptoms (such as diarrhea, constipation, weakness, or dizziness), talking to a doctor should be the next step. Frank blood in the stool, or passing blood with no stool should be reported to a physician as soon as possible. If there's extreme pain and blood loss, it may be necessary to go to the emergency room or to call 911. 

Sources:

Dugdale DC. "Stools - pale or clay-colored." A.D.A.M. 2 Sept 2012.

Heller JL. "Bloody or tarry stools." A.D.A.M. 7 Jan 2011.

National Institute of Diabetes and Digestive and Kidney Diseases. "Bleeding in the Digestive Tract." National Digestive Diseases Information Clearinghouse. November 2004.

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