Yellow, watery diarrhea in adults – what are the causes?

Yellow and watery diarrhea can be a disturbing condition. There are many causes for it. Some benignand some serious.

Yellow, watery diarrhea in adults – what are the causes?
Viktor Simunović, Viktor Simunović
15 March 2024.

Yellow, watery diarrhea in adults is a symptom that can be indicative of a variety of underlying health issues. Each potential cause presents its own unique set of diagnostic challenges and treatment options. Let's further explore these various causes and the potential implications they may have on an individual's health and well-being.

Anxiety or stress

In the domain of psychogenic factors causing yellow, watery diarrhea, anxiety and stress stand prominent, often triggering a series of hormonal and physical responses that can greatly disrupt normal digestive function. Anxiety or stress-induced yellow diarrhea is typically not a cause of yellow coloration but an underlying medical condition.

Stress hormones can stimulate the digestive system, causing an excess of bile—a yellow-green fluid that digests fats. This can lead to changes in stool color, making it appear yellow. Moreover, chronic stress can exacerbate symptoms, causing an overproduction of stomach acid, which can further alter stool color and consistency. Hence, it's important to manage anxiety and stress levels to mitigate this uncomfortable symptom.

Irritable bowel syndrome

Apart from psychological factors like stress and anxiety, certain physical conditions, such as irritable bowel syndrome, can also result in yellow, watery diarrhea.

Irritable bowel syndrome (IBS) is a chronic disorder affecting the large intestine, often leading to a change in stool consistency and bowel movement frequency. Characterized by periods of thorough evaluation and flare-ups, IBS can cause the stool to become loose and watery. Additionally, the stool may turn yellow due to the rapid transit of feces through the intestines, resulting in inadequate absorption of bile salts.

Low bile levels

Another significant cause of yellow, watery diarrhea in adults can be attributed to low bile levels, a condition often associated with a variety of digestive disorders. Bile, a digestive fluid produced in the liver and stored in the gallbladder, plays a critical role in breaking down fats and eliminating waste products from the body.

Its typical green to brown color contributes to the normal brown hue of stool. However, when bile levels are low, the stool can assume a yellow color. Issues with the gallbladder, such as cholecystitis or gallstones, can impede bile production or flow, hence causing yellow stool.

Problems with pancreas

Could pancreatic issues be contributing to episodes of yellow, watery diarrhea in adults? Indeed, the pancreas plays an important role in the digestive tract, releasing powerful enzymes that aid in the digestion of food. When the pancreas becomes inflamed, a condition known as chronic pancreatitis, this process can be disrupted.

In addition to abdominal pain, loss of appetite, and weight loss, chronic pancreatitis can cause the stool to become yellow and watery. This is due to the pancreatic enzymes being unable to reach the digestive tract to break down food properly, leading to malabsorption and a resulting change in bowel movements.


Giardiasis, an intestinal infection caused by the microscopic parasite Giardia, often manifests itself in the form of yellow, watery diarrhea, among other symptoms in adults. The parasite primarily resides in the small intestine, causing inflammation and impairing nutrient absorption, leading to the distinctive yellow poop associated with the condition.

One of the possible causes of giardiasis is the consumption of contaminated food or water. This typically occurs in settings with poor sanitation or during travel to areas where the parasite is common. The symptoms can vary in intensity and duration, from mild discomfort to severe dehydration, necessitating early diagnosis and appropriate treatment.

Intestinal infections

While giardiasis is one specific type of intestinal infection that can cause yellow, watery diarrhea, there are numerous other bacterial, viral, and parasitic infections that can lead to similar symptoms.

These intestinal infections often originate from contaminated food or water and can result in severe vomiting and dehydration. The severity and duration of symptoms usually correlate with the type and cause of the infection. For instance, diseases caused by certain bacteria like E.coli or Salmonella tend to result in abrupt, intense symptoms, often including foul-smelling diarrhea. Conversely, viral infections might exhibit milder symptoms but persist for longer periods.

Liver disease

Liver disease can hinder the normal processing of bilirubin, a byproduct of the breakdown of red blood cells. Normally, bilirubin gives stool a brown color, but if the liver cannot metabolize it properly, the stool may turn yellow.

Additionally, liver disease may lead to gallbladder problems, affecting bile production and storage. If the bile is not adequately concentrated or leaks into the intestines, it could cause diarrhea.


Orlistat, a weight-loss medication, can also contribute to the occurrence of yellow, watery diarrhea in adults. This health condition arises as Orlistat works by inhibiting the absorption of dietary fats, altering the digestion process. Consequently, fat is not broken down or absorbed, leading to loose, oily stools, often manifesting as yellow, watery diarrhea.

Gilbert syndrome

Gilbert syndrome is an inherited liver disorder that can also induce symptoms of yellow, watery diarrhea in adults. This condition affects the body's ability to process bilirubin, a yellowish substance produced by the liver. This can lead to a yellow stool color as the excess bilirubin is excreted in the stool.

Symptoms may include yellowish skin and eyes, and the stool may appear pale or clay-colored. In some cases, Gilbert syndrome may require dietary adjustments or medical treatment to manage symptoms.


In relation to dietary factors, it is important to understand that the consumption of certain foods or substances can greatly influence the appearance and consistency of stool, potentially leading to yellow, watery diarrhea in adults.

Foods rich in fats, for instance, can speed up the transit of food through the intestine, resulting in a yellow, watery stool. Similarly, alcohol can irritate the digestive tract, causing inflammation and an accelerated bowel movement, leading to diarrhea.

Additionally, consumption of certain artificial sweeteners, like sorbitol, can cause diarrhea by drawing water into the bowel.

Finally, intolerance to certain foods, such as lactose, can trigger diarrhea, as the body struggles to break down and absorb these substances in the digestive tract.

Celiac disease

A significant percentage of adults suffering from yellow, watery diarrhea may be experiencing the effects of Celiac disease. In this autoimmune disorder, ingesting gluten leads to small intestine damage. Over time, this can cause the gut lining to become inflamed and incapable of absorbing nutrients, leading to diarrhea.

The coloration can be attributed to the rapid transit of stool through the digestive system, which doesn't allow bile enough time to break down fully. This results in a yellowish hue. A definitive diagnosis of Celiac disease often involves blood tests to check for specific antibodies, followed by an endoscopy to examine the small intestine. Adherence to a strict gluten-free diet is the only effective treatment to help manage symptoms and promote intestinal healing.

Clostridioides difficile infection (C. diff)

Another potential cause of yellow, watery diarrhea in adults is a bacterial infection known as Clostridioides difficile, or C. diff. This bacterium can overgrow in the gut, often following a course of antibiotics that has disrupted the normal gut flora. C. diff produces toxins that cause inflammation of the colon, leading to the characteristic diarrhea, which can be severe.

Risk factors include prolonged antibiotic use, older age, compromised immune systems, and hospitalization or residence in a long-term care facility. Significantly, C. diff infections can recur, causing complications. This bacterium is resistant to many types of disinfectants and can survive on surfaces for long periods, contributing to its transmission.

How to treat yellow, watery diarrhea?

Treating yellow, watery diarrhea effectively requires accurately diagnosing the underlying cause. Depending on the cause, treatment strategies can differ considerably. For dietary issues, a short-term liquid diet may be recommended, followed by a slow reintroduction of fiber. Probiotics may also aid in restoring gut flora balance.

Antibiotics are typically prescribed for bacterial infections. Over-the-counter anti-diarrheal medications can provide temporary relief but should only be used with a physician's guidance. Hydration is paramount, as diarrhea can lead to severe dehydration. Oral rehydration solutions or IV fluids may be necessary in severe cases.

When to see a doctor?

Recognizing the appropriate time to seek medical intervention is essential when dealing with persistent yellow, watery diarrhea symptoms. If symptoms persist beyond two days or are accompanied by severe pain, fever, blood in stool, signs of dehydration like excessive thirst, dry mouth, little to no urination, severe weakness, or dizziness upon standing, immediate medical consultation is necessary.

Chronic or recurring episodes should also warrant a visit to the doctor, as they could indicate underlying conditions such as gastrointestinal disorders, malabsorption syndromes, or even liver disease.

Finally, if over-the-counter medications fail to alleviate symptoms, it is critical to seek professional help. Timely intervention can prevent complications and help manage the condition effectively.

We love to share our knowledge

Related news

EUDoctor Logo
© 2024 EUDoctor, All rights reserved
Developed by