Stool color changes facts
Definition of stool color changes
Stool, feces, or poop is the waste product of digestion. Food mixes with bile from the liver and digestive enzymes from the pancreas allowing protein, carbohydrates, and fats in the diet to be broken down to form a slurry. This liquid mixture passes through the small intestine where nutrients are absorbed into the blood stream and the leftover liquid waste is delivered to the colon. In the colon, water is absorbed and results in stool formation. Normal stool contains bacteria, digested food, cellulose from undigested plant material, and bile. The quality, quantity, and color of stool is an indicator of gastrointestinal health and changes may be significant.
What is the color of normal stool?
Stool (feces) color is most commonly brown. When stool color changes, often, an individual becomes concerned. The presence of the bilirubin (a breakdown product of blood) in bile is generally responsible for stool color. Bilirubin concentration can vary the color of bile color from light yellow to almost black in color. Changes in bilirubin can cause stool to turn green, gray, or clay-like in color. Intestinal bleeding may turn stool black, tarry, red, maroon, or smelly stool. Medication and food may also affect stool color.
Most stool-to-stool changes in color have little meaning. However, some changes, particularly if the changes are consistent over time and not present in only one stool, can be important.
What are the causes of stool color changes?
Stool color changes are not symptoms of disease in most cases. Changes in stool color may be due to:
What are symptoms of stool color changes?
Changes in stool color usually is a symptom of a disease or condition.
Green stools
If stool passes through the intestine too quickly, there might not be enough time for bile to be digested and broken down to provide the normal brownish stool color. Bile is a greenish brown fluid that is manufactured in the liver and stored in the gallbladder. Bile helps digest fats in food. It takes time for the bile to degrade and turn brown in the intestine and if the transit time is short, the stool remains green colored. This is why diarrhea is often greenish in color.
Green stools may be a normal variant. It can also be caused by a diet rich in green vegetables, especially spinach. Iron supplements also may be a cause, though it often turns stool black.
Yellow, greasy, and foul smelling stool
There are a variety of reasons why stool will be yellow and greasy appearing. It can be due to the intestine's inability to digest fat because of malabsorption such as in celiac disease and cystic fibrosis, or because the pancreas is unable to manufacture adequate digestive enzymes.
Yellow poop can be caused by a gastrointestinal infection by giardiasis, a protozoan infection that can cause significant diarrhea.
Black tarry stools
Black stools are a worrisome symptom because it may be due to bleeding into the gastrointestinal tract, most often the esophagus, stomach or duodenum. Red blood cells are broken down by digestive enzymes and turn the stool black. These stools tend to be tarry and foul smelling. This can be a medical emergency; black tarry stools should not be ignored.
Blood from nosebleeds or from dental procedure and injuries can be swallowed and may be the cause of black stool.
Certain foods and medications can turn stool black, including iron, bismuth (Pepto Bismol, loperamide [Kaopectate]), beets, and licorice. While the stools may be black, they also tend to be gritty and not tarry. Pregnant women may have black stools due to prenatal vitamins, which contain iron.
Bright red stools
The most common cause of bright red stool is bleeding from hemorrhoids, but other bleeding causes are much more significant. For that reason, blood in the stool should never be ignored. Other causes include infection, inflammatory bowel disease (Crohn's disease, ulcerative colitis), diverticular bleeding, tumors, and arteriovenous malformations (AVM). Brisk bleeding from the upper GI tract may cause stools to be red instead of black because there has not been enough time for the red blood cells to be digested. Red food coloring and beets can also give a reddish hue to the stool.
Light-colored white or clay-colored stools
White or clay colored stool are often seen with liver or biliary tract diseases. Lack of bile which gives stool its brown color leaves it appearing pale.
Maroon stools
Maroon colored stools are often due to bleeding in the GI tract. Classically, the source of bleeding for red stools is the upper GI tract (esophagus, stomach, duodenum), while the colon is the source for bright red blood. Maroon stools may arise from the small intestine (jejunum, ileum) and proximal colon, but these are not hard and fast rules. How bright the red color is depends not only upon the location of bleeding, but also how quickly the blood moves through the intestine. The faster the stool moves through the GI tract, the brighter red the color. This can be an emergency situation.
Mucous in the stool
Mucous in the stool may be a normal variant, and it may cover segments of formed feces. However, it also can occur in patients with inflammatory bowel disease or cancer. Mucous that is also associated with blood and/or abdominal pain should not be ignored and requires medical attention. Mucous in stool can also be seen in patients with irritable bowel syndrome.
Stool that floats
Most stool floats because of poor absorption of nutrients or excess flatus (gas). It is a normal variant and usually of no concern. Changes in diet can lead to stool that floats, but as an isolated symptom, no action needs to be taken and often it resolves spontaneously. Stool does not float because of increased fat content.
Malabsorption syndromes that are associated with floating stool include lactose intolerance, celiac disease, cystic fibrosis, and short bowel syndrome.
Changes in the size and shape of stool
Each person has their own size, shape and consistency of stool. It is the change in stool pattern that matters more than the absolute size and shape of stool. Narrow stool, sometimes called pencil-thin, may occur occasionally and is of no concern. People with irritable bowel syndrome may develop thinner stools.
A person with "normal" stools that has a new change in the caliber (diameter, length, width) of the bowel movement should consult his/her doctor. This may be a sign of a narrowed or scarred colon, perhaps due to a tumor, but the health care professional may want further information by taking a history and performing a physical examination before being concerned about that conclusion.
How is the cause of stool color changes evaluated?
In most cases, a diagnosis, if any, cannot be made by stool color alone.
The patient and the doctor need to consider other symptoms, past medical history, dietary changes, and medications to help decide what has caused the stool to change color. Physical examination will be important to help decide the significance of the stool color.
Stool may be tested to look for blood, fat or infection. Blood tests may be necessary depending upon the clinical situation.
What are symptoms of stool color changes?
Changes in stool color usually is a symptom of a disease or condition.
Green stools
If stool passes through the intestine too quickly, there might not be enough time for bile to be digested and broken down to provide the normal brownish stool color. Bile is a greenish brown fluid that is manufactured in the liver and stored in the gallbladder. Bile helps digest fats in food. It takes time for the bile to degrade and turn brown in the intestine and if the transit time is short, the stool remains green colored. This is why diarrhea is often greenish in color.
Green stools may be a normal variant. It can also be caused by a diet rich in green vegetables, especially spinach. Iron supplements also may be a cause, though it often turns stool black.
Yellow, greasy, and foul smelling stool
There are a variety of reasons why stool will be yellow and greasy appearing. It can be due to the intestine's inability to digest fat because of malabsorption such as in celiac disease and cystic fibrosis, or because the pancreas is unable to manufacture adequate digestive enzymes.
Yellow poop can be caused by a gastrointestinal infection by giardiasis, a protozoan infection that can cause significant diarrhea.
Black tarry stools
Black stools are a worrisome symptom because it may be due to bleeding into the gastrointestinal tract, most often the esophagus, stomach or duodenum. Red blood cells are broken down by digestive enzymes and turn the stool black. These stools tend to be tarry and foul smelling. This can be a medical emergency; black tarry stools should not be ignored.
Blood from nosebleeds or from dental procedure and injuries can be swallowed and may be the cause of black stool.
Certain foods and medications can turn stool black, including iron, bismuth (Pepto Bismol, loperamide [Kaopectate]), beets, and licorice. While the stools may be black, they also tend to be gritty and not tarry. Pregnant women may have black stools due to prenatal vitamins, which contain iron.
Bright red stools
The most common cause of bright red stool is bleeding from hemorrhoids, but other bleeding causes are much more significant. For that reason, blood in the stool should never be ignored. Other causes include infection, inflammatory bowel disease (Crohn's disease, ulcerative colitis), diverticular bleeding, tumors, and arteriovenous malformations (AVM). Brisk bleeding from the upper GI tract may cause stools to be red instead of black because there has not been enough time for the red blood cells to be digested. Red food coloring and beets can also give a reddish hue to the stool.
Light-colored white or clay-colored stools
White or clay colored stool are often seen with liver or biliary tract diseases. Lack of bile which gives stool its brown color leaves it appearing pale.
Maroon stools
Maroon colored stools are often due to bleeding in the GI tract. Classically, the source of bleeding for red stools is the upper GI tract (esophagus, stomach, duodenum), while the colon is the source for bright red blood. Maroon stools may arise from the small intestine (jejunum, ileum) and proximal colon, but these are not hard and fast rules. How bright the red color is depends not only upon the location of bleeding, but also how quickly the blood moves through the intestine. The faster the stool moves through the GI tract, the brighter red the color. This can be an emergency situation.
Mucous in the stool
Mucous in the stool may be a normal variant, and it may cover segments of formed feces. However, it also can occur in patients with inflammatory bowel disease or cancer. Mucous that is also associated with blood and/or abdominal pain should not be ignored and requires medical attention. Mucous in stool can also be seen in patients with irritable bowel syndrome.
Stool that floats
Most stool floats because of poor absorption of nutrients or excess flatus (gas). It is a normal variant and usually of no concern. Changes in diet can lead to stool that floats, but as an isolated symptom, no action needs to be taken and often it resolves spontaneously. Stool does not float because of increased fat content.
Malabsorption syndromes that are associated with floating stool include lactose intolerance, celiac disease, cystic fibrosis, and short bowel syndrome.
Changes in the size and shape of stool
Each person has their own size, shape and consistency of stool. It is the change in stool pattern that matters more than the absolute size and shape of stool. Narrow stool, sometimes called pencil-thin, may occur occasionally and is of no concern. People with irritable bowel syndrome may develop thinner stools.
A person with "normal" stools that has a new change in the caliber (diameter, length, width) of the bowel movement should consult his/her doctor. This may be a sign of a narrowed or scarred colon, perhaps due to a tumor, but the health care professional may want further information by taking a history and performing a physical examination before being concerned about that conclusion.
How is the cause of stool color changes evaluated?
In most cases, a diagnosis, if any, cannot be made by stool color alone.
The patient and the doctor need to consider other symptoms, past medical history, dietary changes, and medications to help decide what has caused the stool to change color. Physical examination will be important to help decide the significance of the stool color.
Stool may be tested to look for blood, fat or infection. Blood tests may be necessary depending upon the clinical situation.
Source: http://www.rxlist.com
Malabsorption syndromes that are associated with floating stool include lactose intolerance, celiac disease, cystic fibrosis, and short bowel syndrome.
Source: http://www.rxlist.com
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