Yes, it is normal for stools to sink. It can be a sign of healthy stool. Stools may float if they contain excess gas, which may occur with a high fiber diet, or if the stool contains higher fat levels.

Stool consistency, shape, and whether they sink or float can be useful signs of gastrointestinal health.

Brown, well-formed, soft stools that sink to the bottom of the toilet bowl tend to indicate a healthy bowel movement.

Stools that float may indicate excess gas or fat in the stool. It may also be a sign of infection or another health condition.

This article looks at why stools may float and what to look for in the shape, consistency, and smell of stools.

there are two bathrooms in a black and white photoShare on Pinterest
tomap49/Getty Images

A floating or sinking stool may reveal a person’s bowel health. In some cases, floating stool may be a sign of an underlying health issue.


Stools may float due to trapped gas, which causes them to be less dense and float. Around 10–15% of people may produce floating stools because of trapped gas.

According to a 2020 study, dietary fiber may result in the body holding on to more gas and affect how gas passes out of the body.

Greasy or fatty stools

“Steatorrhea” is the medical term for increased fat in stools. It can cause fatty, oily stools that float and may be difficult to flush. The stools may also be pale, bulky, and foul-smelling.

Fatty stools may occur from:

Pancreatitis, which is inflammation of the pancreas, may cause greasy, foul-smelling stools and diarrhea.


Giardiasis is an infection affecting the intestines. It occurs from ingesting the Giardia parasite.

Giardiasis can cause floating, greasy stools that have a foul smell. Other symptoms include:

  • gas
  • diarrhea
  • abdominal pain or cramping
  • nausea
  • upset stomach
  • dehydration

Various prescription medications can help treat giardiasis.

The color of stools can change due to the foods and drinks people consume, but it can also be a sign of certain health conditions.

According to the Canadian Digestive Health Foundation, healthy stools are usually brown.


Pale, white, or clay-like stools may indicate an issue with the liver or bile ducts. White stools may also be a side effect of some medications.


Sometimes a stool may look green if people eat a diet high in leafy green vegetables, which is not a concern.

Green stools without eating leafy green vegetables may indicate an infection or antibiotic use.

If stools move too quickly through the digestive tract, they may not have enough time to turn the typical brown color.

People can contact a doctor if they have green stools with no known cause.


Black stools can indicate blood in the stools from an underlying medical condition, such as ulcers or other bleeding lesions in the upper gastrointestinal tract.

Pepto-Bismol and iron supplements can also turn stools black. Otherwise, black stools indicate internal bleeding and require medical attention.


Red stools can indicate blood in the stool, indicating internal bleeding.

Unless people have eaten large amounts of red food dye or red foods, such as beets, they need to talk with a doctor for red stools.


Yellow stools may indicate celiac disease or an issue with the liver, gallbladder, or pancreas.

Yellow stools with a foul smell may indicate malabsorption issues.

People can contact a doctor if they have stools that are pale or white, yellow, black, or red.

Learn about poop colors with a helpful chart here.

Healthcare professionals may use the Bristol Stool Chart to assess the shape and consistency of stools to help them diagnose gastrointestinal conditions.

According to the chart, a normal stool shape and consistency is smooth, soft, and sausage-shaped. A stool may have some cracks in it, but it is still easy to pass.

If stools are hard and lumpy, or in small hard balls, it may be a sign of constipation. Stools that are soft, mushy blobs can be a sign of loose bowel movements. Liquid stools indicate diarrhea.

Stool smells can vary, particularly through eating different types of food. However, especially foul-smelling stools may indicate an underlying health issue.

An infection, such as giardiasis, may cause foul-smelling stools. People can contact a doctor if they have strong-smelling black or tarry stools.

Normal and healthy bowel movements can vary in frequency for each person. Regular bowel movements can indicate a healthy bowel and may range from one to three times daily to three times a week.

Passing fewer than three bowel movements a week may be a sign of constipation.

Frequently passing stools that are loose or watery is a sign of diarrhea. People can seek medical help if they pass six or more loose stools within 24 hours.

Stools that sink to the bottom of the toilet bowl can be a sign of a healthy bowel movement. Stools may float for various reasons, such as containing higher levels of gas or fat.

In some cases, floating stools may indicate an underlying health issue, such as malabsorption, an infection, or an issue with the pancreas.

If people have stools that persistently float and appear greasy or oily, or if people have any other unusual symptoms, they can contact a doctor.