Should I Worry About My Poop Color?

Do you look into the toilet bowl after pooping?

Many of us do, especially those who struggle with digestive issues because it’s a well known way to monitor gut health. Poop characteristics, particularly its color, provides you with vital information about what’s going on inside.

Understanding why these color changes occur helps address certain health issues. While some color changes are simply related to the color of food you ate, other changes may indicate severe medical conditions.

This article helps answer the question, “Should I worry about my poop color?”

Poop Formation

Poop, also referred to as feces or stool, is the solid waste humans eliminate.

The food we eat goes from the mouth to the stomach to the small intestine, and eventually reaches the colon, also referred to as the large intestine. Food, now called chyme, is mostly digested and absorbed upon reaching the colon. However, absorption of water as well as bacterial fermentation occurs here, helping produce short chain fatty acids and certain vitamins.

The end-product of digestion is poop, which is stored in the rectum until it’s ready for elimination.  Poop consists of mostly water as well as bacteria, protein, fiber, fat, and other organic solids. The amount of each of these components varies based on the person’s’ diet and health status.

Keep in mind it takes about 18 to 72 hours for food to become poop. This process, also known as intestinal transit time, may be shortened in cases of diarrhea and lengthened in cases of constipation.

What is “Normal” Poop?

Normal poop can say a lot about your health status.

It’s typically described as light to dark brown in color and semi-solid with a light mucus coating. The brown color comes from bile, bilirubin particles, and dead red blood cells. Additionally, it contains about 75% water and appear like a soft and smooth sausage.

 Most refer to the Bristol Stool Scale for help classifying characteristics of poop. Essentially, the amount of time chyme spends in the colon impacts how the final product appears and how easy it is to pass. A healthy goal is type 4 on the chart below.

Bristol Stool scale

Other features indicating normal or healthy poop include a “S”-shape, 1 to 2 inches in diameter, and a “natural” odor. There is no set standard for normal bowel movement frequency, which can range from 3 per day to 3 per week.

Green Poop

Poop may appear green for a variety of reasons.

1. Green Foods

Consuming high amounts of foods with green pigments may produce green colored poop.

Green pigments may come from natural sources like chlorophyll in sea vegetables or leafy greens. Additionally, green pigments may come from artificial sources like green food coloring in processed foods and candies.  

 2. Excess Bile

It’s important to note that bile, the fluid that helps with fat digestion, naturally has a green-yellow hue.

Excess bile in the poop also produces a green color. This may occur when there is inadequate time for the body to reabsorb bile and therefore it ends up being excreted.

Conditions that speed up intestinal transit time like inflammatory bowel disease (IBD), celiac disease, irritable bowel disease (IBS) may all result in green poop. Additionally, excess use of laxatives, caffeine and alcohol produce a similar effect.

3. Changes to Microbiome

Factors that change the bacterial composition of the gut can also change the color of poop, typically to green. Parasitic, viral and bacterial infections, medical procedures, and antibiotic use all potentially impact the microbiome.

Yellow Poop

Yellow poop is often a red flag for poor fat digestion.

Often, one may experience greasy and foul smelling poop along with the yellow color. These are all signs that the body struggles to properly digest and absorb fats.

Conditions impacting the pancreas like celiac disease, cystic fibrosis, chronic pancreatitis, and/or pancreatic cancer all potentially reduce the pancreas’ ability to manufacture and release digestive enzymes. Without adequate flow of these enzymes, fat doesn’t breakdown and absorb normally.

In addition to enzymes, the body also needs bile to digest fats. Liver cancer, hepatitis, cirrhosis, and gallstones can all potentially reduce bile production and/or flow, resulting in poor fat digestion and yellow poop.

Black Poop

Black poop can reflect food intake or more serious conditions like gut injuries or cancer.

Black Foods

Foods that may produce a dark black hue to your poop include blueberries, blackberries, black licorice, and even deep red foods like beets, red gelatin and fruit punch.

Be sure to thoroughly review your diet for potential darkly hued foods that may contribute to black poop.


Depending on where the bleeding occurs, poop can appear black or tarry.

A gut injury occurring higher up in the digestive tract (i.e. the esophagus to the lower small intestine) creates the appearance of dark black or tarry poop because the blood is broken down by digestive enzymes. Also, reduced blood flow to the digestive tract can also create this appearance.


Poop color alone is not a sign of cancer; however, it is important to inform your doctor and seek further workup.

Remember, poop appears black, but it is due to blood. Please see the section on “Why is There Blood in My Poop?” to learn more.

Medications & Supplements

Iron supplements, bismuth subsalicylate products (i.e. Pepto-Bismol and Kaoepectate), and other medications may cause black poop.

Bloody Poop

Blood in poop is typically related to conditions that cause gut injuries, but can also be related to your diet.

Red Foods

Foods that may create a similar red-blood appearance in your poop include those with natural and artificial red hues.

These include processed foods, juices, red gelatin, and candies as well as beets, cranberries, and tomato products. Review your diet for potential sources of red color contributing to a bloody appearance of your poop.

Gut Injuries

The brightness of the blood relates to the potential location of the gut injury.

Injuries on the lower intestines often produce a bright red color, whereas injuries on the upper intestine produce a darker red and sometimes black color. Also, intestinal transit time impacts the shade of blood in poop. When things move through the gut faster, this usually produces a brighter red color.

Intestinal injuries can be caused by numerous factors:

  • Hemorrhoids: enlarged blood vessels in or around the anus
  • Colon polyps: a small clump of cells that form in the colon
  • Anal fissures: a tear in the lining of the anus
  • Diverticular bleeding: diverticula (small pouches) in the colon rupture
  • Tumors: abnormal growth of tissue, may be benign or malignant
  • Ulcers: intestinal sores common in IBD, may also be present in the esophagus, stomach, duodenum, colon or rectum
  • Excessive straining: too much force to relieve solid waste
  • Arteriovenous malformations: arteries or veins rupture due to abnormal communication
  • Low platelet count: reduce ability to form blood clots

Mucus in Poop

A small amount of mucus is your poop is normal, but when you notice too much it may indicate a problem.

Mucus is secreted to help moisten and lubricate the inside of the colon. This helps poop to pass through easily, with minimal straining.  If you notice increased amounts of mucus or accompanied symptoms like blood, abdominal pain or changes in stool consistency, then this should warrant further workup with your doctor.

Ulcers along the intestines produce mucus. Therefore, conditions that produce ulcers like Crohn’s, ulcerative colitis or even cancer may be present.

Additionally, diarrhea may result in excess mucus, so intestinal infections and IBS could also be potential causes. 

Should I Be Concerned?

Changes in stool color happens to most of us and is typically not a sign of concern.

Pay attention to these signs as your poop color may be indicating something more severe:

  • The poop color change is persistent
  • Other symptoms accompany the color change including upset stomach, nausea, vomiting, cramping, itchy anus, etc.
  • You find large amounts of blood
  • The poop is tarry and foul smelling

Please seek the help of a doctor if you notice these symptoms. Further workup including a physical exam, stool and blood tests, scans, endoscopy and colonoscopy may be warranted.

Preventing Poop Color Changes

Poop color is one sign when assessing the health of your digestive tract.

Normal, healthy poop ranges from light to dark brown. Changes in poop color from green to yellow to black to red all indicate potential problems. They can also reflect specific colorful foods consumed in excess.

To prevent drastic changes in poop color, ensure proper gut care. Drink plenty of water, eat enough fiber-rich foods, and avoid eating foods with artificial food colors.

Seek proper care from your doctor for any on-going change to your poop color as it can be a sign of concern.


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