Stool color, texture, and form changes facts
- The normal stool (poop, feces) which is generally colored from light to dark brown.
- Although in stool color or texture changes may be normal but most changes should be assessed.
- Stool color changes have symptoms, if any, can be the symptoms of the underlying cause of the change, for example, foods, drinks, or illnesses which may include:
- Diet (beets, diets rich in green vegetables, licorice)
- Bismuth (for example, Pepto-Bismol)
- Gallbladder disease
- Celiac disease
- Ulcerative colitis
- Crohn’s disease
- Diverticular disease
- An unusual color stool may be because of diarrhea; bleeding in the intestine; pancreas, or liver diseases; and medications
- A common stool color change is green stool or poop which may be due to bile pigment in the stool because diarrhea moves food too quickly thorough the intestine so the intestinal chemicals and bacteria can’t break down the bile pigment to its normal brown color, or the green color may be because of some foods like green, leafy vegetables or green food coloring.
- A sign of bleeding in the digestive tract (from the esophagus, stomach, small intestine, or colon) can be for red or black poop and should not be ignored.
- Tests that are required to be done when the stool color changes depend upon what cause is suspected for the change in stool color. For example, gastrointestinal tract endoscopy may be needed to assess red or black stools if bleeding is suspected.
- The treatment of the underlying cause is the treatment required for changes in stool color.
Rectal Bleeding (Blood in Stool, Hematochezia)
Blood in Stool – Causes
Bright red, maroon in color, black and tarry, or occult (not visible to the naked eye) can be sign of blood in stool. Blood in stool caused can range from harmless, annoying conditions of the gastrointestinal tract such as hemorrhoids to critical conditions such as cancer.
Symptoms – Stool Color Changes
Symptoms are not caused alone due to changes in stool color. Any symptoms are responsible for the underlying cause of the change in stool color, texture, or form
Usually light to dark brown in color, and there is moderate variation among individuals with respect to stool color, quantity, and form is found generally in bowel movements. When occurrence of changes in stool happen, it can mean that there may be an illness affecting the gastrointestinal (GI) tract or the entire body.
What is the color of normal stool?
Brown is mostly the color of stool (feces, poop). Changes in stool color make a person, parent, or caregiver often concerned. Responsible for stool color is the presence of the bilirubin in the bile which is a breakdown product of the hemoglobin in red blood cells that are normally destroyed after a useful life of several weeks. The color of stool can differ from light yellow to almost black in bilirubin concentration. The cause of stool turning to green or yellow can be due to the changes in the chemical structure of the bilirubin. If stool is dilute or there is a reduction in the amount of bilirubin that is produced by the liver then yellow stool may occur. Acting on the bilirubin and changing its color can be because of the bacteria and digestive enzymes in the intestine. There is little meaning in most stool-to-stool changes in color. However, some changes, particularly if there are consistent changes over the period of time and not present in only one stool may mean something needs to be examined.
Causes – Stool Color, Texture, and Form Changes
Poop color changes are not symptoms of disease in most of the cases. Changes in stool color may be because of:
- Diarrhea may cause yellow-green stools.
- Some foods (beets, Jell-O, Kool-Aid, licorice, green leafy vegetables)
- A few over-the-counter (OTC) and prescription medications
- Diseases affecting the liver, pancreas, and intestines
- Bleeding from the intestinal tract
If passing of the stool through the intestine too quick, enough time might not be available for bile to be digested and broken down to provide the normal brownish stool color. Normally, chemically changing bile to a greenish-brown color is due to the bacteria in the intestine. Time is taken for the bile to be completely changed in the intestine and becoming brown again, and if the time of transmitting is short, for example, when a person is having diarrhea, the stool remains green colored.
Variant in green stools may be a normal. Green poop may also be caused due to a diet which is rich in green vegetables, especially spinach, or Iron supplements, though iron often turns stool black.
Yellow, greasy, and foul smelling stool
A variety of reasons is present for why stool will be yellow, greasy, and foul smelling. The reason could be due to the intestine’s inability to digest and absorb fat because of diseases of the intestinal lining such as in celiac disease and cystic fibrosis as the pancreas is not able to produce adequate digestive enzymes such as with chronic pancreatitis or pancreatic cancer that blocks the pancreatic duct, or enough bile is not there being delivered to the intestine such as in cancer of the liver or bile ducts that are blocked. Undigested fat can be the cause of yellowness, greasiness, and foul smell.
Bright red stools
- Bleeding from hemorrhoids is the most common cause of bright red-colored stool in adults
- In infants, an anal fissure or tear in the tissue surrounding the anus can be a common cause.
- Bright red blood in the stool may have other causes which may be more serious such as:
- Infections of the intestines
- Inflammatory bowel disease (Crohn’s disease, ulcerative colitis)
- Diverticular bleeding
- Arteriovenous malformations which are the abnormal communications between arteries and veins in the wall of the intestine that ruptures.
- An ulcer in the esophagus, stomach, or duodenum can have brisk bleeding which may also cause stools to be red instead of black if there has not been enough time for the red blood cells to be digested.
- A reddish color in the stool can also be due to red food coloring and beets
Black tarry stools
A worrisome symptom can be black stools because it may be due to a large amount of bleeding into the digestive system, mostly from the upper GI tract including the esophagus, stomach, and duodenum. Digestive enzymes in the intestine break down the red blood cells and turn the stool black which can make the stools to be tar-like (sticky) and foul smelling. Black tarry stools should not be ignored as it might be an medical emergency.
Swallowing blood caused from nosebleeds or from dental procedures or mouth injuries may be the cause of black stool, but the amount of bleeding generally is not substantial enough to do this.
Clay-colored or white stools (pale stools)
Liver diseases or bile ducts can occur due to light-colored or clay-colored stool. Pancreatic cancer blocking the bile ducts can be cause of pale stool. Stool losing its brown color and leaving it appearing pale can be due to lack of bile.
Bleeding in the GI tract can be a cause of maroon colored stools. The upper GI tract (esophagus, stomach, duodenum) is the source of red bleeding stools, while the colon is the source for bright red blood. Partial digestion of the blood in the intestine causing maroon stools often arises from the small intestine (jejunum, ileum) and proximal colon, but the color also depends in part on how rapidly the blood travels through the intestines. The brighter the red color will depend on how faster the stool moves through the GI tract which can be an emergency.
In intussusception which is found in children, where one part or the intestine telescopes into another part, where a temporary obstruction is caused, stools may be described as currant jelly in color and consistency.
Mucus in the stool
It may be normal to have Mucus in the stool, and it may cover segments of formed feces. However, in people with inflammatory bowel disease or cancer it can also happen. Medical attention is required when mucus is related with blood and/or abdominal pain which should not be ignored. People having irritable bowel syndrome (IBS), mucus in the stool can also occur.
Drugs that change stool color
Drugs that turn the stool black and include iron and bismuth (contained in Pepto-Bismol and Kaopectate) are the most common medications that change the stool color. Nevertheless, change in the color of stool to black or other colors is also related to large number of other drugs. The importance of this fact practically is that the cause of change in stool color with any new drugs or dietary supplements needs to be considered.
Stool that floats
An excessive amount of gas is contained making most stool floats which is normal and has little meaning. Stool that floats can also be led by changes in diet, but as an isolated symptom, no action is required to be taken, and often it resolves spontaneously. An increased amount of fat is not the reason of stool that floats. Oil droplets are caused by fat in stool in the toilet bowl.
Increased amounts of gas to form in the intestines theoretically may lead to floating stool if caused by any conditions, especially in conditions where there is malabsorption of nutrients such as with lactose intolerance, celiac disease, cystic fibrosis, and short bowel syndrome.
Changes in the size and shape of stool
Size, shape, and stool consistency differs with people. Pattern of the change in stool is what matters more than the absolute size and shape of stool. Narrow stool, sometimes known as pencil-thin, may happen occasionally and can be of no concern. Thinner stools may be developed in people with irritable bowel syndrome (IBS).
Nevertheless, healthcare professional should be consulted if a person with normal stools that has a new change in the diameter, length, width (caliber) of the bowel movement which can be a sign of a narrowed or scarred colon, perhaps because of a tumor, but further information may be needed by the health care professional about accompanying symptoms or tests.
Having two or even three stools in a morning are not unusual. A more solid form may be usually in the first stool because it has been in the colon (where water is absorbed) the longest. The second will be looser, and if there is a third stool, it will be the loosest. The development of looser or firmer than normal stools is another change in stool form that often needs evaluation. At one end of the spectrum is constipation and at the other end is diarrhea so consistent, milder changes in either direction need to be examined even if the change does not reach these levels.
Type of doctors treating stool color changes
Most often, primary health care provider will ask questions about the stool color which may include health care professionals who care for infants and children. Depending upon the cause of the stool color change, involvement of certain specialists may be needed. For example, for red or black stool because of bleeding, endoscopy may be performed by a gastroenterologist, to look for a bleeding source in the stomach or intestine. The specialist that helps manage other diseases of the intestinal tract, including Crohn’s disease, pancreatitis, and celiac disease, that can cause color changes because of poor absorption of nutrients from the diet is known as gastroenterologists.
In most cases, a diagnosis of the stool color, 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.
To look for blood, fat, or infection, stool may be tested. Depending upon the clinical situation, blood tests may be important. Depending on the change in color, it may be important to examine the pancreas, liver or GI tract.
Contacting doctor about stool color or texture changes
Urgent assessment and treatment may be needed aside from black, red, or maroon stools that may mean bleeding is a possibility as most color changes are not an emergency. The importance is determined based on other symptoms that might be there.
Changes are often noted in their bowel pattern for women who are pregnant. Due to iron and vitamin supplements the stool may turn black. Stool can also turn greenish due to iron. Constipation may happen and hemorrhoids can be developed and cause blood in the stool as the uterus enlarges and increasing pressure within the pelvis.
If no underlying problem is present, changes in stool color are often because of changes in the diet and will resolve in a couple of days. If this is not the case and changes are continuous, health care professional should be contacted and medical attention needs to be sought.
Doctor should be contacted if having stool color changes and having related symptoms such as vomiting, diarrhea, fever, or abdominal pain.
It is essential to keep in mind that every person is different and changes in bowel habit which may include color, size, frequency, or consistency (hard or soft) may be normal for one person or a sign of a potential problem for another.
Stool color chart
|Black||GI bleeding||This is an emergency|
|Black||Iron, bismuth||Cannot presume this to be the reason for the stool color|
|Maroon||Gastrointestinal bleeding||This is an emergency|
|Red||Hemorrhoids||Only one of the potential causes. Do not ignore|
|Red||Inflammatory bowel disease||Consult health care professional|
|Red||Infection, diverticular bleed||Consult health care professional|
|Red||Tumor, rapid upper GI bleed||Consult health care professional|
|Green||May be normal||Consult health care professional|
|Green||Diet high in green vegetables||Consult health care professional|
|Green||Associated with diarrhea||Consult health care professional|
|Brown||Normal color||Consult health care professional|
|Yellow||Diseases of the pancreas||Malabsorption|
|Yellow||Celiac disease, cystic fibrosis||Consult health care professional|
|Yellow||Giardia infection||Consult health care professional|
|Clay, pale yellow or white||Liver or biliary disease||Lack of bile in the stool|