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Greasy Stool: Causes & Common Questions

Greasy stool may be hard to flush, and can point to a disorder in the gut, such as pancreatitis, IBS, food intolerances, colitis, or gallstones. It also may mean you're not absorbing enough nutrients so it's important to get treated if it keeps happening.
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Last updated April 9, 2024

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8 most common cause(s)

Steatorrhea, or fatty stool, symptoms explained

Now and then, all of us might suffer from greasy or fatty stools that typically float in the toilet and are hard to flush. Occasional fat in the stool is normal, especially after a very rich meal at a fancy French restaurant, for example, where you probably feasted on high-fat foods. However, persistent fatty stools are not normal and may indicate some type of disorder in the gut. Because greasy stool symptoms typically indicate an inability to absorb fats and, therefore, fat-soluble vitamins, the condition must be addressed to prevent deficiency in these nutrients.

Greasy stool, or steatorrhea, means that you have too much fat in your stool. Sometimes, this condition can be caused by weak bile in the system, as bile helps us to break down the fats in our stool effectively and absorb all our fat-soluble vitamins from them, like vitamins A, E, D, and K. Too much fat in the stool can also be a sign of malabsorption, meaning you aren't absorbing nutrients well when food passes from the stomach into the intestines.

Consistently greasy stools are a sign of some problem with fat absorption in the body.[4] Over time, such inability to absorb fats can cause all kinds of problems, as essential fatty acids are crucial to virtually all of of our systems, from keeping our eyes moist and liquid, to keeping our skin youthful, to manufacturing hormones. So see a doctor if greasy stool symptoms are a persistent problem.

If you have steatorrhea you'll typically notice a cluster of symptoms that accompany the fatty stool such as:

What causes fatty, oily stool?

Greasy stools are a sign of a malabsorption of fats in the digestive tract. A wide range of diseases and disorders can cause this problem with absorption.

Most common causes of greasy stools:

  • Pancreatitis: The pancreas manufactures enzymes that help us break down fats properly. They work in conjunction with bile (produced by the liver) to break fat globules down into tiny fat particles and help us extract nutrients from our foods. If the pancreas is not functioning properly, you may not be breaking down fat effectively, causing the greasy stool.
  • Whipple disease: This disease is caused by a bacterial infection in the intestines. Whipple's disease negatively impacts your body's ability to break down both fat and carbohydrates and is a common cause of malabsorption and greasy stool.
  • Food intolerances: Allergies and intolerances to foods like dairy or gluten can also impact nutrient absorption in the gut, leading to fatty stools.
  • Irritable Bowel Syndrome (IBS), Inflammatory Bowel Disease (IBD), and Crohn's disease: All of these conditions of the bowel and intestine are inflammatory conditions that impact how well nutrients and fats are absorbed by the body. Therefore, gut issues like these can all cause greasy, fatty stools.
  • Cystic fibrosis: This disease, usually symptomatic since early childhood, causes the mucous membranes in the body to become sticky as mucus becomes thick. This mucus blocks ducts and valves, or passages in the pancreas, and prevents the normal release of bile and enzymes that break down fat. Greasy, foul-smelling stools are one of the hallmark symptoms of this disease.

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Ulcerative colitis

Ulcerative colitis means there are sores, or ulcers, on the inner lining of the large intestine. This causes the chronic inflammation within the large intestine known as colitis. It is a form of inflammatory bowel disease.

The exact cause of ulcerative colitis is not known, but family history and an autoimmune disorder within the large intestine are thought to be involved. Most susceptible are those under age 30 and over age 60.

Symptoms include abdominal pain and cramping; diarrhea with blood; nausea; loss of appetite; weight loss; and fatigue. There may also be fever, anemia, and joint pain.

Diagnosis is made through patient history; physical examination; blood tests; stool sample tests; and, in some cases, endoscopic examination of the large intestine with biopsy of the damaged tissue.

Treatment involves referral to a gastroenterologist and addressing the abnormal autoimmune response. Medications such as corticosteroids or immunomodulators will be prescribed, often for life, along with acetaminophen for pain, antibiotics for infection, and changes in diet. Surgery may be tried in some cases.

Pancreatic cancer

Pancreatic adenocarcinoma is also called pancreatic exocrine cancer, and means that tumors have begun to grow in the exocrine cells of the pancreas. These cells manufacture the enzymes that help digest fats. The tumors may be benign (not cancerous) or malignant (cancerous.)

The exact cause of any pancreatic cancer is unknown. Risk factors include smoking; obesity; alcoholism; exposure to certain chemicals; family history of the disease; and pre-existing diabetes, pancreatitis, or cirrhosis of the liver.

Symptoms include jaundice, which is a yellowing of the skin and eyes; dark urine; pale-colored stools; abdominal and/or back pain; loss of appetite; and unintended weight loss.

Diagnosis is made through patient history; physical examination; blood tests; abdominal imaging such as ultrasound or CT scan; and sometimes biopsy of the pancreas or other minor surgical procedures to help make the diagnosis.

Treatment involves a combination of several methods, including chemotherapy; radiation therapy; surgery to remove all or part of the pancreas as well as to help relieve some of the symptoms of the disease; pain management; and psychological support.

Rarity: Rare

Top Symptoms: fatigue, nausea, loss of appetite, diarrhea, unintentional weight loss

Urgency: Primary care doctor

Irritable bowel syndrome (IBS)

Irritable bowel syndrome is commonly known as IBS. Normally, the muscles of the colon, or large intestine, contract and relax to push food along. It's thought that in IBS, the muscles randomly contract either too strongly or too weakly and therefore cause alternating bouts of diarrhea or constipation.

The exact cause is not known. Food allergy/intolerance; stress; hormonal imbalance; and infection or bacterial overgrowth in the colon may play a role, as well as an overly sensitive gastrointestinal nervous system.

Pre-menopausal women who suffer from depression or lead very stressful lives may be most susceptible.

Symptoms vary among individuals, and often come and go. These include abdominal pain and cramping; bloating; gas; diarrhea; and constipation. IBS is not associated with serious illnesses such as cancer, but symptoms may interfere with quality of life.

Diagnosis is made through patient history, physical examination, and ruling out any other cause. Imaging may also be done.

Treatment begins with improved diet and stress management. Antibiotics, antidepressants, and other medications may be attempted.

Diabetes insipidus

Diabetes insipidus (DI) is caused by a lack of or decreased sensitivity to the hormone vasopressin. Vasopressin is needed for the kidneys to concentrate urine, making sure you do lose to much fluids. If this function is impaired, it will result in urinating frequently and large amounts, extreme thirst, and dehydration.

You should visit your physician to discuss these symptoms. It is likely a urine test and blood test will be ordered.

Rarity: Rare

Top Symptoms: fatigue, irritability, constipation, excessive thirst, dry mouth

Urgency: Primary care doctor

Cystic fibrosis

Cystic fibrosis (CF) is an inherited disease of the mucus and sweat glands, affecting multiple organs, especially the lungs. The mucus clogs the lungs, causing breathing problems and making it easy for bacteria to grow. This can lead to problems such as repeated lung infections and lung damage.

Rarity: Rare

Top Symptoms: shortness of breath, productive cough, salty-tasting skin, decreased exercise tolerance, recurring problem with leaking urine

Urgency: Primary care doctor

Chronic hepatitis C

hepatitis B, or "hep B," is a viral liver infection. It is spread through direct contact with the blood or other bodily fluids of an infected person, especially through sexual contact and/or sharing needles. A baby can be infected by the mother during birth; however, the newborn can receive a vaccine to protect it.

Symptoms appear one to four months after exposure and include abdominal pain; nausea and vomiting; joint pain; fever; dark urine; and jaundice, which is yellowing of skin and whites of eyes.

If not treated, hepatitis B can become chronic – especially in children. This increases the risk of developing liver failure, liver cancer, or cirrhosis (damage from scarring.) hepatitis B is a medical emergency and requires immediate care.

Diagnosis is made through blood tests and sometimes through liver biopsy.

Acute hepatitis B can be managed with rest, fluids, and good nutrition while the body fights the virus. However, a chronic infection may be treated with antiviral medications or liver transplants.

There is a vaccine for hepatitis B, recommended for anyone at risk.

Rarity: Common

Top Symptoms: fatigue, nausea, muscle aches, loss of appetite, joint pain

Symptoms that never occur with chronic hepatitis c: pain in the lower right abdomen, pain in the lower left abdomen, pain in the upper left abdomen, pain around the belly button

Urgency: Primary care doctor

Chronic gallstones

Gallstones are small, pebble-like, mineral deposits that can form inside the gallbladder. They may cause no symptoms unless they become lodged in a duct leading out of the gallbladder.

Gallstones are thought to be caused by high cholesterol, which can form into crystals in the gallbladder; by cirrhosis, or scarring, of the liver; or by incomplete emptying of the gallbladder.

Most susceptible are women over age 40. Other risk factors are obesity, lack of exercise, poor diet, and rapid weight loss as with gastric bypass surgery.

Symptoms include sudden sharp pain in the center or upper right abdomen, in the right shoulder, and in the upper back. There may also be nausea and vomiting, yellowing of skin and eyes, and fever and chills.

It's important to see a medical provider for these symptoms. Gallstones can lead to pain, infection, and further complications.

Diagnosis is made through physical examination, CT scan, blood tests, and sometimes specialized scans to examine the gallbladder system.

Treatment usually involves surgery to remove the stones and sometimes the gallbladder itself.

Rarity: Uncommon

Top Symptoms: nausea, loss of appetite, unintentional weight loss, vomiting, pain in the upper right abdomen

Urgency: Primary care doctor

Celiac disease

Celiac disease is also called gluten-sensitive enteropathy, coeliac, or sprue. It is an autoimmune response in the gut to gluten, a protein in wheat, rye, and barley.

Repeated exposure to gluten causes damage to the lining of the small intestine.

Most at risk are Caucasians with:

  • Family history of celiac disease.
  • Down syndrome.
  • Type 1 diabetes.
  • Rheumatoid arthritis.
  • Autoimmune thyroid disease.

Symptoms include digestive upset with gas, bloating, and diarrhea. The malnutrition causes fatigue, weight loss, fragile bones, severe skin rash, mouth ulcers, anemia, and damage to the spleen and nervous system.

A swollen belly, failure to thrive, muscle wasting, and learning disabilities are seen in children, and normal growth and development can be severely affected.

Diagnosis is made through blood testing and endoscopy, and sometimes biopsy of the small intestine.

There is no cure for the condition, but celiac disease can be managed by removing all gluten from the diet. Nutritional supplements will be used and sometimes steroid medication is given to help heal the gut.

Rarity: Rare

Top Symptoms: fatigue, stomach bloating, nausea, constipation, diarrhea

Urgency: Primary care doctor

Acute pancreatitis

Acute pancreatitis is the inflammation of the pancreas, which creates and releases insulin and glucagon to keep the sugar levels in your blood stable. It also creates the enzymes that digest your food in the small intestine. When these enzymes accidentally get activated in the pancreas, they digest the pancreas itself, causing pain and inflammation.

You should go to the ER. There, diagnosis is made by physical examination, imaging, and blood tests. Treatment typically involves intravenous (IV) fluids and medicines to control the pain.

Rarity: Rare

Top Symptoms: constant abdominal pain, nausea or vomiting, being severely ill, severe abdominal pain, fever

Symptoms that always occur with acute pancreatitis: constant abdominal pain

Urgency: Hospital emergency room

Gallstones

Gallstones are small, round deposits found in the gallbladder, the organ where bile is stored. Gallstones can be subclassified a number of ways. Oftentimes, gallstones will be referred to as either cholesterol stones or pigment stones depending on the makeup of the gallstone.

Gallstones can also be class...

How to treat steattorhea

To treat greasy stools or steatorrhea, any doctor or gastroenterologist will first want to isolate the cause of the problem. Because there are so many gut and organ conditions that can contribute to a problem with fat absorption, he or she will run a battery of stool tests.

For individuals with weak bile or who don't have a gallbladder, which stores and concentrates bile, supplemental bile salts or pancreatic enzymes can help the individual break down fat better, enabling them to absorb fat-soluble vitamins and essential fatty acids.

For food allergies and intolerances, simple avoidance of triggers will resolve the problem [10]. For more serious diseases, from pancreatitis cystic fibrosis, medications, and lifestyle changes are typically the course of action.

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FAQs about greasy stool

Here are some frequently asked questions about greasy stool.

What foods cause greasy stools?

Greasy stool is generally a sign of intestinal malabsorption, associated with conditions such as celiac disease, chronic pancreatitis, lactase deficiency, and so on. These conditions disrupt processes of fat breakdown/absorption. In principle, any food that exacerbates these underlying conditions can cause greasy stool. There is less evidence regarding the association between the consumption of whole nuts, natural and artificial fats with greasy stools.

Can coffee cause greasy stools?

There have been no studies linking coffee and greasy stool. Caffeine in coffee is a potent stimulator of smooth muscles in the intestinal tract and thus might have an impact on bowel function. Sometimes dairy products in coffee can contribute to greasy stool among patients with lactase deficiency.

Why do I have oily stools when pregnant?

Oily, fatty, or greasy stools can be caused by intrahepatic cholestasis of pregnancy (ICP)[15]. Cholestasis is a term used to describe conditions with diminished bile formation and/or excretion as bile is essential to fat absorption. ICP can cause fat malabsorption and, hence, oily stool [2]. ICP typically develops in the late second and/or third trimester and rapidly resolves after delivery. This condition also causes pruritus (itching of the skin) and an elevation in serum bile acid concentrations. The etiology of ICP is not completely understood but likely involves a combination of genetic susceptibility, hormonal factors, and environmental factors.

Can you have greasy stools after gastric bypass surgery?

Yes. Certain gastric bypass surgeries, such as jejunoileal bypass, biliopancreatic diversion, and Roux-en-Y gastric bypass can cause greasy tools. These procedures shorten the length of the functional small intestine to reduce the effectiveness of nutrient absorption, which contributes to greasy stools.

Why do my stools float?

Stools that float are usually fatty or greasy and are most often due to poor absorption of nutrients (malabsorption) or too much gas (flatulence)[2]. Flatulence can be caused by the consumption of foods that are hard to digest, such as fiber, or food that your body cannot tolerate. Malabsorption can be caused by many conditions with compromised processes of food breakdown/absorption.

Questions your doctor may ask about greasy stool

  • Have you experienced any nausea?
  • Have you been feeling more tired than usual, lethargic or fatigued despite sleeping a normal amount?
  • Any fever today or during the last week?
  • Have you had any changes in your weight?

Self-diagnose with our free Buoy Assistant if you answer yes on any of these questions.

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The stories shared below are not written by Buoy employees. Buoy does not endorse any of the information in these stories. Whenever you have questions or concerns about a medical condition, you should always contact your doctor or a healthcare provider.
Dr. Rothschild has been a faculty member at Brigham and Women’s Hospital where he is an Associate Professor of Medicine at Harvard Medical School. He currently practices as a hospitalist at Newton Wellesley Hospital. In 1978, Dr. Rothschild received his MD at the Medical College of Wisconsin and trained in internal medicine followed by a fellowship in critical care medicine. He also received an MP...
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References

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  8. Whipple Disease. National Institute of Diabetes and Digestive and Kidney Diseases. Published August 2014. NIDDK Link.
  9. Ruiz AR. Whipple Disease. Merck Manual Professional Version. Updated February 2018. Merck Manual Professional Version Link.
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  11. Irritable Bowel Syndrome (IBS). National Institute of Diabetes and Digestive and Kidney Diseases. NIDDK Link.
  12. Phillips MM. Inflammatory Bowel Disease. U.S. National Library of Medicine: MedlinePlus. Published July 9, 2017. MedlinePlus Link.
  13. What is Crohn's Disease? National Institute of Diabetes and Digestive and Kidney Diseases. Published September 2017. NIDDK Link.
  14. Cystic Fibrosis. National Heart, Lung, and Blood Institute. NHLBI Link.
  15. Intrahepatic Cholestasis of Pregnancy. U.S. National Library of Medicine: Genetics Home Reference. Published October 23, 2018. GHR Link.