Most stool changes in color and shape vary in meaning and sometimes or most are not serious conditions. However, some changes, particularly if the changes are consistent over time and not present in a single bowel movement, may mean that something needs to be investigated. Read on to learn about the variants that can occur when evacuating and what may be their cause.
What is the normal color of the stool?
The color of stool (poop) is most commonly brown. When the color changes, a person, parent, or caregiver often worries. The presence of bilirubin in bile (a breakdown product of hemoglobin in red blood cells that is normally destroyed after a lifespan of several weeks), is generally responsible for stool color.
The concentration of bilirubin can vary the color of the stool from light yellow to almost black. Changes in the chemical structure of bilirubin can cause it to turn green or yellow. Yellow stools can also occur if they are thin or if there is a reduction in the amount of bilirubin produced by the liver. Bacteria and digestive enzymes in the intestine can act on the bilirubin and change its color.
Stool color and its possible meaning
As we have mentioned, bowel movements are usually light brown to dark brown in color, and there is moderate variation between individuals with respect to the color, amount, and shape of stool.
When these changes in the stool occur, it may mean that there may be a disease that affects the gastrointestinal (GI) tract or the entire body.
Symptoms associated with changes in stool color, if any, are symptoms of the underlying cause of the change, for example, from foods and beverages such as beets, diets rich in vegetables, licorice, etc., and by conditions or diseases such as:
· Gallbladder disease
· Celiac Disease
· Ulcerative colitis
· Crohn's disease
· Diverticular disease
Changes in stool color can be due to diarrhea, bleeding in the intestine, diseases of the intestines, liver or pancreas, and medications.
When the color changes, the tests that should be done depend on the suspected cause of the change in stool color. For example, gastrointestinal (GI) endoscopy may be necessary to evaluate red or black stools if bleeding is suspected.
Red or black stools can be a sign of bleeding in the gastrointestinal tract (from the esophagus, stomach, small intestine, or colon) and should not be ignored.
When stool color changes, the tests that should be done depend on what cause is suspected for the stool color change. For example, gastrointestinal (GI) endoscopy may be necessary to evaluate red or black stools if bleeding is suspected. Treatment for stool color changes is to treat the underlying cause.
The most common cause of bright red stools in adults is bleeding from hemorrhoids. In infants the most common cause is an anal fissure or tear in the tissue around the anus.
Other causes of blood in the stool can be more serious, such as:
· Infections of the intestines
· Inflammatory bowel disease (Crohn's disease, ulcerative colitis)
· Diverticular hemorrhage
· Arteriovenous malformations (abnormal communications between arteries and veins in the wall of the intestine that break).
· Heavy bleeding from an ulcer in the esophagus. The stomach or duodenum can also cause stools to be red instead of black if there has not been enough time for the red blood cells to be digested.
Red food coloring and beets can also give a reddish tone when evacuating and the red-orange color is observed in people with essentially carnivorous habits.
There are a variety of reasons why your stool will be yellow, and there is a variety that is even greasy and smelly. The latter may be due to the inability of the intestine to digest and absorb fat due to diseases of the intestinal lining (as in celiac disease and cystic fibrosis), because the pancreas is unable to manufacture adequate digestive enzymes, due to diseases such as Chronic pancreatitis or pancreatic cancer that blocks the pancreatic duct, or there is not enough bile to deliver to the intestine. The yellow and greasy with a foul smell is due to undigested fat. There is a lemon yellow color that is also prevalent in strict vegetarians.
It is usually seen in the second session when cleaning the hepatic flexure of the colon in patients with a history of liver disease and in patients who take many medications chronically.
The green color of the stool is a common changing color. Also, it is due to the pigment of the bile when there is diarrhea, since it moves food too quickly through the intestine and it is thus that the chemical cannot be broken down. The green color can be due to certain foods like green vegetables, greens, or green food coloring.
If there has been no ingestion of dyes or animal blood, we must consider the possibility that there is a problem of blood loss in some section of the upper digestive tract.
Black stools are also a worrisome symptom, because it can be due to a large amount of bleeding in the gastrointestinal tract, most often from the upper GI tract, including the esophagus, stomach, and duodenum. Red blood cells are broken down by digestive enzymes in the intestine and turn the stool black. They tend to be tarry (sticky), and smell foul. This can be a medical emergency. Black tarry stools should not be ignored.
Blood from nosebleeds or dental procedures or mouth injuries can be swallowed and can be the cause of black stools, but the amount of bleeding is usually not substantial enough to produce it.
Others: in addition to squid ink or blood sausages, the ingestion of some vegetables (spinach, green), table beets (red), etc. can mislead us.
Clear, white or clay colored stools
The pale stools or clay, are often observed with liver disease or the bile ducts. It can also be caused by pancreatic cancer that blocks the bile ducts. The lack of bile causes them to lose their brown color and makes them appear pale.
Medications that change stool color