In normal stool (feces), there is a mixture of water and unabsorbed nutrients, including fibers, proteins, fats, and salts. There are also other wastes, such as mucus, bacteria, and dead cells, that are excreted as part of the feces. When there is too much fat in the stool it is called steatorrhea, or fatty stool. 

Too much fat in the stool might be caused by the consumption of too many fatty or greasy foods, or it may be a sign of maldigestion or malabsorption. This is when your body isn’t properly digesting or absorbing nutrients, or it isn’t making the compounds necessary to effectively digest the food you eat.

This article discusses the symptoms and potential causes of steatorrhea. It also covers risk factors and when to seek tests or treatment for your symptoms. 

Symptoms of Steatorrhea

Symptoms of steatorrhea include:

  • Foul smelling stools
  • Stools that float
  • Mucousy, frothy, or foamy stools
  • Diarrhea or loose bowel movements that are bulkier than normal
  • Oily stools or stools covered in a greasy film
  • Pale or light-colored stools
  • Abdominal pain or cramping
  • Abdominal bloating
  • Indigestion or heartburn
  • Flatulence (gas)

Complications Associated With Steatorrhea

Chronic or severe steatorrhea may be associated with other symptoms of malabsorption. These include:

  • Malnutrition
  • Dehydration
  • Weight loss
  • Stunted growth in children
  • Muscle weakness and pain
  • Chronic fatigue
  • Weak bones, or osteoporosis
  • Dry, scaly skin rashes

Causes of Steatorrhea

Sometimes after eating meals very high in fat or fiber that is difficult to digest you might experience fatty stools or steatorrhea. Examples of food that can cause steatorrhea include whole nuts, high fat fish, natural fat (e.g. jojoba oil and fish oil), artificial fat (e.g. olestra), and excessive alcohol.

This occasional occurrence is usually not something to be concerned about. However, if you are experiencing too much fat in your stools on a regular basis, it can be a sign of something more serious. 

Steatorrhea can occur if your digestive system isn’t able to effectively break down the fats in the food you are eating. Your body may also not be able to properly absorb some of the nutrients in the food you eat, including fat.

Some causes of steatorrhea include:

  • Cystic fibrosis (an inherited disorder that results in mucus buildup in the digestive tract and lungs and blocks digestive enzyme secretion)
  • Pancreatic diseases
  • Liver or biliary disease
  • Celiac disease (an autoimmune disease in which gluten triggers a reaction)
  • Gallbladder disease or removal
  • Crohn’s disease (an inflammatory bowel disease)
  • Infections of the digestive tract
  • Damage or injury to the intestines
  • Gastric bypass surgery
  • Lactose intolerance (inability to break down the milk sugar lactose)

Fat absorption requires three components including bile acids, digestive enzymes such as pancreatic and small bowel enzymes, and the normal absorption function of a healthy small bowel. Therefore, steatorrhea can be broadly categorized by three different causes based on a deficiency of any of these components.

Exocrine Pancreated Insufficiency

The first is exocrine pancreatic insufficiency (EPI). Exocrine relates to a secretion that is released outside an organ. and insufficiency is the inability to perform its normal function. This is when there are not enough pancreatic enzymes (proteins that help speed up chemical reactions) for normal fat breakdown or digestion.

The result is fat remaining in your stool instead of being digested in your body. EPI most commonly occurs due to chronic, or long-term, inflammation of the pancreas and loss of acinar cells (the functional unit of the exocrine pancreas).

EPI causes maldigestion of food and is often associated with medical conditions that affect the pancreas, such as cystic fibrosis and chronic pancreatitis (inflammation of the pancreas).

Bile Salt Deficiency

Another common reason for steatorrhea is bile salt deficiency. This is due to impaired bile salt production or decreased secretion of bile salts. Bile salts are a main component of bile and are needed by the body to help break down fats, aid in digestion, absorb vitamins, and eliminate toxins.

Steatorrhea related to bile salt deficiency may also be due to reduced circulating bile acids. This can happen if you have had your gallbladder removed, have liver disease or failure, or experience biliary atresia (blockage of the tubes that carry bile from the liver to the gallbladder), or it might be due to other diseases of the bowel.

Malabsorption

The third category of steatorrhea causes is malabsorption due to intestinal conditions that affect the absorption capacity of the bowel.

These include surgical resection of the bowel, inflammation of the bowel, medications, or other conditions that affect bowel function including celiac disease, Crohn’s disease, Whipple disease (a rare bacterial infection), and other malabsorption syndromes.

What Medications Can Cause Steatorrhea?

Some medications can cause changes to your stool, including steatorrhea. One medication in particular that causes fatty, loose stools is Alli or Xenical (orlistat). Orlistat is a lipase inhibitor, which means it works to prevent some of the fat in foods that are consumed from being absorbed in the digestive tract, keeping it in the stool.

How to Treat Steatorrhea

In order to treat steatorrhea, you must first identify the underlying cause. Depending on the underlying cause, your treatment options may vary. Working with your healthcare provider to correctly diagnose the cause of your steatorrhea and any associated maldigestion or malabsorption is best when seeking treatment.

Mild or acute cases of steatorrhea may be treated at home. This includes:

  • Resting
  • Staying hydrated
  • Avoiding meals and snacks very high in fat
  • Avoiding meals and snacks very high in fiber
  • Over-the-counter antidiarrheal medications
  • Over-the-counter medications for indigestion
  • Quitting or reducing smoking
  • Limiting or avoiding alcohol

If your steatorrhea is associated with a medical condition that is treated with diet, changing what you consume can help. For example, avoid foods and beverages with lactose if you are lactose intolerant. If you are diagnosed with celiac disease, avoiding all foods and beverages containing gluten is important to help decrease symptoms.

Sometimes a combination of dietary changes, along with medication and nutritional supplements, are needed to treat conditions that cause steatorrhea. For example, people with EPI need to ensure they are eating a healthy, nutrient-rich diet, and take pancreatic enzymes with each meal and snack, as well as vitamins and supplements to ensure they are getting all the nutrients they need.

Consult your healthcare provider if you have chronic or severe steatorrhea that is associated with other symptoms of malabsorption.

Are There Tests to Diagnose the Cause of Steatorrhea?

To diagnose steatorrhea, your doctor will usually ask about your symptoms, review your medical history, and might order a test to check the fat content of your stool.

For a stool test, stool is collected over a period of 72 hours while you consume a diet containing a certain amount of fat per day, usually 100 grams daily. Excreting 7 grams of fat or less over a 24-hour period is considered normal when consuming 100 grams of fat. If the amount of fat in the stool is high (more than 7 grams), it suggests that the body is not absorbing fat and steatorrhea may be diagnosed.

If your doctor diagnoses steatorrhea, you will most likely need additional testing to identify the underlying cause.

Your doctor might order additional tests and procedures to look for signs of malabsorption associated with steatorrhea.

For example, a biopsy (a procedure that removes cells or tissue from your body) of the small intestine may be done. Your doctor will examine your intestines by passing an endoscope (​​a medical device with a light attached) through your mouth and into your small intestine to collect tissues for additional tests. Sometimes, a special staining of the biopsy is needed if an infectious cause like Whipple disease is suspected.

Other tests to take images of organs such as the pancreas may also be ordered in some cases.

When to See a Healthcare Provider

Mild to moderate acute cases of steatorrhea may be unpleasant, but can usually be safely treated at home. If however, other symptoms associated with steatorrhea lead to more serious complications, contact your doctor. These include:

  • Dehydration
  • Unintended weight loss
  • Stunted growth in children
  • Muscle weakness and pain
  • Chronic fatigue or exhaustion
  • Fever
  • Easy bruising or bruising that takes a long time to heal
  • Dry, scaly skin rashes

Severe or chronic steatorrhea requires attention by your healthcare provider, as it may be a sign of a more serious underlying medical condition. Contact your healthcare provider to help identify the cause for your steatorrhea.

Summary

Steatorrhea, or fatty stool, may be caused by diet, or it may be a sign of malabsorption, such as seen in cystic fibrosis or some pancreatic diseases. Signs of steatorrhea include stool that is foul-smelling, greasy, oily, mucousy, or foamy and is bulkier than usual. 

Most mild or acute cases can safely be treated at home. However, severe or chronic cases require medical attention to determine the underlying cause of the steatorrhea. Identifying and treating the underlying cause can help resolve symptoms associated with steatorrhea.

A Word From Verywell  

Steatorrhea can be unpleasant and concerning. If you have fatty stool that only lasts a short time, there is usually nothing to be concerned about. Long-term steatorrhea may be due to malabsorption or another medical condition. 

Working with your healthcare team is crucial to ensuring your body is properly digesting and absorbing the food and nutrients you consume. With the right treatment plan, you can reduce or resolve your symptoms of steatorrhea and resume a healthy and normal quality of life.

Frequently Asked Questions

  • What foods cause steatorrhea?
  • Eating meals very high in fat and/or fiber might cause acute steatorrhea. Common foods high in fat and/or fiber include deep-fried foods, cookies, cakes, chips, fatty fish such as salmon, coconut or palm oils, whole nuts, and whole grains.If you are lactose intolerant, foods with lactose might trigger you to have steatorrhea. Additionally, if you have celiac disease, consuming foods or beverages containing gluten may cause steatorrhea.
  • Learn More:
  • Causes of Loose Stool and How to Fix It
  • Can steatorrhea cause weight loss?
  • One sign of chronic steatorrhea includes unintentional weight loss. This is because the fatty stool is often related to a medical condition that causes malabsorption of fat and other nutrients in the digestive tract. When important nutrients are not properly digested and absorbed, they do not reach the different cells and organs in the body to help them function effectively. The end result is the fat and nutrients remaining in the stool and being excreted from the body, and if it occurs over a long period of time, weight loss may be seen.
  • Learn More:
  • Exocrine Pancreatic Insufficiency (EPI) Symptoms
  • What does steatorrhea stool look like?
  • Steatorrhea, or fatty stools, are foul-smelling and may be loose and bulkier than usual. They will float and may appear to be filled with mucus, froth, or foam, and will be lighter in color. You might notice a greasy film covering the stool or drops of grease or oil in the toilet water or on the toilet paper.
  • Learn More:
  • Should You Worry About Changes in Your Stool’s Appearance?
  • Does celiac disease cause steatorrhea?
  • People with celiac disease have symptoms that vary. However, in classical celiac disease, people often have signs and symptoms of malabsorption. This includes diarrhea and steatorrhea, or fatty, foul-smelling, pale stools.
  • Learn More:
  • Symptoms of Celiac Disease

Eating meals very high in fat and/or fiber might cause acute steatorrhea. Common foods high in fat and/or fiber include deep-fried foods, cookies, cakes, chips, fatty fish such as salmon, coconut or palm oils, whole nuts, and whole grains.

One sign of chronic steatorrhea includes unintentional weight loss. This is because the fatty stool is often related to a medical condition that causes malabsorption of fat and other nutrients in the digestive tract. 

Steatorrhea, or fatty stools, are foul-smelling and may be loose and bulkier than usual. They will float and may appear to be filled with mucus, froth, or foam, and will be lighter in color. You might notice a greasy film covering the stool or drops of grease or oil in the toilet water or on the toilet paper.

People with celiac disease have symptoms that vary. However, in classical celiac disease, people often have signs and symptoms of malabsorption. This includes diarrhea and steatorrhea, or fatty, foul-smelling, pale stools.