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What Causes Yellow Stool?

By 9th February 2024Gut Health
What Causes Yellow Stool

What is a Normal Stool Colour?

While it’s possible to have a spectrum of stool colours in the stool, the colours that are considered normal are shades of brown and sometimes green.

The colour of the normal stool is influenced by the food that has been eaten but also by bilirubin, which is produced in the liver.

It’s also possible for the colour of the stool to change to a different colour than normal. This might be a shade of red, orange or yellow. For some, these might be concerning but there can be simple explanations for the change in stool colour from brown to yellow. [Source: PubMed]

IBS Stool Colour ChartWhat Does Yellow Stool Indicate?

A common age for there to be yellow stool is during infancy. During the first months of life, the digestive system goes through changes which alter digestive processes which can lead to a change in stool colour.

During infancy, this is most likely due to stool travelling quickly through the digestive tract. This can lead to higher levels of bile remaining in the stool. Due to bile being yellow, this may lead to more of a yellow stool in babies, particularly those being breastfed. [Source: PubMed]

Other possible causes of yellow stool include:

  1. Liver and gallbladder disorders
  2. Disorders that affect the pancreas
  3. Coeliac disease
  4. Gilbert’s syndrome
  5. Giardiasis
  6. Bile acid malabsorption

Does IBS Cause Yellow Stool?

IBS does not always lead to changes in stool colour and for a diagnosis of IBS, a change in stool colour is not required.

A common factor seen in IBS is diarrhoea. This increase in transit time means that food and stool pass through the digestive system at an increased speed. If this happens then the stool can change colour. 

This can be due to undigested food remaining in the stool leading to the stool becoming more of the colour of the food. It’s also possible for more bile to remain in the stool which is yellow.

For those with IBS and constipation, the stool can become darker in colour. This can be due to the reabsorption of water that takes place in the large intestine. If the stool remains in the large intestine for longer (which is the case in constipation) the stool becomes more dehydrated which turns the stool a darker shade of brown. [Source: PubMed]

Why is the toilet paper yellow when I wipe?

The colour left on the toilet paper will generally be the same as the colour of the stool. This commonly means that if the stool appears more yellow in colour, a similar shade will be seen on toilet paper.

In some individuals, mucus can be present in the stool. Mucus is a gel-like substance that is naturally produced in the gut in small amounts. When the gut becomes irritated more mucus can be produced to provide a form of protection. It’s then possible for this mucus to be seen in the stool or on the toilet paper.

Typically, the colour of the mucus can range from clear to brown colour. However, in some cases, this can also be yellow (due to the colour of the stool) which may leave a yellow mucus on the toilet paper after wiping.

Can Vitamin Deficiency Cause Yellow Stool?

It has not been found that yellow stool itself causes vitamin deficiencies. However, it has been found that those with IBS are at great risk of deficiencies in certain nutrients.

These deficiencies can include:

  • Vitamin D
  • Vitamin B2
  • Calcium
  • Iron [Source: PubMed]

This is understood to be related to factors such as diarrhoea which increases the speed of digestion. This may contribute to food moving too quickly through the bowel for the nutrients to be absorbed.

It is also possible that irritation or low-grade inflammation may alter how nutrients are absorbed. This can lead to nutrients remaining in the stool, and not being absorbed by the body. 

Additionally, as bile is required to help digest fats and fat-soluble vitamins if bile flow is impacted (which can be another cause of yellow stool), further deficiencies may also be present. 

This may impact levels of:

  • Vitamin A
  • Vitamin D
  • Vitamin E
  • Zinc [Source: PubMed]

Coeliac Disease and Yellow Stool

Having yellow poo (stool) does not mean that coeliac disease is present, however, for some, it can be a symptom of coeliac disease.

This may be the result of bile acid malabsorption which is related to the damage to the gut lining present in coeliac disease. 

Bile acids are released into the small intestine via the gallbladder to aid in the digestion of dietary fats. As they travel through the bowel, they are reabsorbed and recycled. However, if the gut lining is impacted this reabsorbed does not take place which leads to bile acids remaining in the stool.

This can lead to diarrhoea as well as yellow stool. This is due to the bile being yellow. [Source: PubMed]

Coeliac disease can also increase the risk of steatorrhea, which is the presence of fat in the stool. This can also be related to malabsorption. In most cases this may lead to a light or clay-coloured stool, it may also be possible for this to be yellow.

If Coeliac disease is present strict avoidance of gluten-containing foods is required. [Source: PubMed]

Also Read: Can Stress Cause Blood In The Stool?

Parasites and Yellow Stool

Giardia is a parasite that can cause a range of digestive systems. These symptoms can include:

  • Abdominal pain
  • Water stool/diarrhoea
  • Nausea
  • Foul-smelling gas and/or stool
  • Greasy stool
  • Change in stool colour
  • Fever
  • Reactive arthritis
  • Weight loss
  • Nutrient deficiencies [Source: PubMed]

As with coeliac disease, a gastrointestinal parasitic infection can lead to fatty stool which may be yellow in colour. It may also be related to the malabsorption of bile in the gut during an infection. [Source: PubMed]

Pancreas and Yellow Stool

Issues with the pancreas may also lead to a yellow stool. This can be due to the reduction in either the production or secretion of pancreatic enzymes into the digestive system.

Issues leading to reduced functioning of the pancreas include:

  • Pancreatitis
  • Pancreatic cancer
  • Cystic fibrosis
  • Diabetes
  • Inflammatory bowel disease
  • Coeliac disease [Source: PubMed]

Does Yellow Poop Mean Infection?

An infection in the bowel can be one cause of poop being yellow. This can be due to poor absorption of fats or bile in the gut.

However, other causes are possible. These include issues with the liver and gallbladder or pancreas as well as coeliac disease, Gilbert’s syndrome and bile acid malabsorption. [Source: PubMed]

What are the Complications of Yellow Stool?

If the stool is yellow, the underlying causes can provide more information on the possible complications. 

If any of the following symptoms are present alongside yellow stool, medical attention would be required.

  • Rectal bleeding
  • Chronic abdominal pain
  • Perianal fistula or abscess
  • Chronic diarrhoea
  • Nocturnal symptoms. 

This would be to consider complications that may require medical attention. [Source: PubMed]


Medical causes of yellow stool should be considered and ruled out. However, it is possible for issues in the gut, such as IBS, to lead to changes in stool colour.

Working with a gut health nutritionist to take into consideration the causes of gut imbalances (such as SIBO and dysbiosis) can be important when addressing gut symptoms.