Understanding Steatorrhea: Causes, Symptoms, and Effective Treatments

When it comes to health, what you see in the toilet bowl might be more revealing than you'd think. The appearance of your stool can provide critical clues about your body's inner workings, potentially signaling the presence of underlying conditions that need attention.

One such warning sign is steatorrhea – loose stools that are bulky, pale, and oily. Paying attention to and recognizing these changes can lead to earlier diagnosis and treatment of underlying digestive disorders, including chronic pancreatitis, celiac disease, and gastrointestinal (GI) infections.

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What Is Steatorrhea?

Steatorrhea refers to excess fat in the stool, which is a sign of maldigestion or malabsorption in the GI tract.

Most fat digestion occurs in the small intestine, where bile acids and pancreatic enzymes break down and emulsify large fat molecules into smaller droplets for absorption. If this process is disrupted, fat isn't absorbed properly, leading to fat malabsorption and steatorrhea.

Steatorrhea Symptoms

The hallmark symptom of steatorrhea is greasy, pale, and bulky stools that have a foul odor and float in the toilet due to their high-fat content. These stools may also be difficult to flush. (41)

Patients may also experience additional symptoms, depending on what is causing the steatorrhea. These can include:

Bloating
Abdominal pain and cramping
Frequent diarrhea
Weight loss
Anemia
Oral ulcers
Dermatitis herpetiformis (an itchy, blistering rash associated with celiac disease)
Jaundice (yellowing of the skin)
Itching

Steatorrhea in Different Populations

Steatorrhea can impact individuals across all demographics, making it essential to screen for this condition in all populations as a potential sign of underlying disease.

Steatorrhea can indicate underlying conditions in children that can negatively impact their growth and development, leading to failure to thrive.

For older adults, chronic malnutrition is associated with increased mortality, morbidity, and physical decline, translating to reduced quality of life and the inability to perform activities of daily living independently.

Causes of Steatorrhea

The most common causes of steatorrhea can be subclassified under the following categories:

1. Conditions Leading to Exocrine Pancreatic Insufficiency (EPI)

EPI is the inability to digest and absorb nutrients properly, particularly fats, due to the pancreas's failure to produce enough digestive enzymes. It is most commonly caused by chronic pancreatitis and cystic fibrosis. Other causes include alcohol use disorder, pancreatic cancer, and Zollinger-Ellison syndrome. (42)

2. Bile Acid Deficiency States

The liver produces bile, which is stored in the gallbladder and released into the intestine to help digest fats. Diseases of the liver and bile ducts can interfere with the bile synthesis and the transportation of bile acids to the small intestine, leading to a state of bile acid deficiency. Examples include (42):

Primary biliary cholangitis: an autoimmune disease that causes inflammation and destruction of the liver's bile ducts
Primary sclerosing cholangitis: a chronic liver disease that causes inflammation, scarring, and narrowing of the bile ducts
Cholestasis: the slowing of bile flow through the liver and bile ducts
Liver disease

3. Diseases Affecting the Small Intestine

The following conditions affecting the small intestine can impair fat digestion and absorption:

Celiac disease: an autoimmune disorder triggered by gluten that damages the intestinal lining
Crohn's disease: a type of inflammatory bowel disease (IBD) that causes inflammation and scarring in the intestines
Small intestinal bacterial overgrowth (SIBO)
Bacterial infections of the GI tract
Parasitic infections like Giardia lamblia

Rare and Uncommon Causes

Abetalipoproteinemia is a rare genetic disorder (affecting less than one in one million people) in which the body has trouble making and absorbing certain fats, including cholesterol. It's caused by a mutation in a gene that codes for a protein that helps create proteins called lipoproteins, which help transport fats through the bloodstream. Abetalipoproteinemia typically presents in infants as failure to thrive, steatorrhea, and abdominal distension. Over time, it can also lead to more serious issues like vision problems and nerve damage.

Steatorrhea can also result from certain surgical procedures, such as bariatric surgery for weight loss or removal of a portion of the small intestine to treat an underlying condition. These procedures can impair fat absorption by reducing the absorptive surface area of the intestines. (3, 39)

Diagnosis and Evaluation

Steatorrhea is typically diagnosed by examining stool characteristics and conducting fecal fat tests to confirm the presence of excess fat. Identifying the underlying cause requires a comprehensive evaluation, which may involve specialized tests and imaging. Your doctor may refer you to specialists during this process, such as a gastroenterologist or dietician.

Step 1: Clinical History and Physical Examination

Your doctor will begin a diagnostic workup for steatorrhea with a thorough medical history and physical examination, asking about:

Oily, bulky, and foul-smelling stools
Pale or clay-colored stools
Unintentional weight loss
Bloating, gas, and abdominal discomfort
Fatigue or weakness
Symptoms of vitamin deficiencies (e.g., night blindness, easy bruising)
Family history of GI disorders
Dietary habits, including fat intake and recent dietary changes
Alcohol use
Recent travel history, particularly to areas where parasitic infections are common
History of GI or bariatric surgeries

Step 2: Laboratory Tests

Your doctor will order a fecal fat test to measure the amount of fat excreted in your stool to confirm fat malabsorption. The gold-standard testing method is the coefficient of fat absorption, which requires patients to eat 100 grams of fat daily for five days and collect all feces for the last three days of the dietary challenge. A positive test for fat malabsorption is more than 7 grams of fat per day or more than 21 grams in 72 hours. (31, 40)

Additional tests are recommended to narrow the list of possible causes of steatorrhea, including:

D-Xylose Test: A diagnostic procedure used to assess the absorptive capacity of the small intestine. During the test, the patient ingests a specific amount of D-xylose, a simple sugar that is normally absorbed in the small intestine. Blood and urine samples are then collected at set intervals to measure the concentration of D-xylose. Low levels of D-xylose in the blood or urine can indicate malabsorption issues. (22)
Fecal Elastase: A stool test that measures the level of elastase, an enzyme produced by the pancreas, with a single stool sample. Low levels (less than 100 mcg/g) are diagnostic for EPI. (2)
Fecal Calprotectin: Calprotectin is a protein found in white blood cells. Elevated calprotectin levels in the stool can indicate inflammation in the GI tract, such as in conditions like IBD, celiac disease, and bacterial infections.
Stool Culture and O&P (Ova and Parasites) Testing: These stool tests are diagnostic procedures for pathogenic bacterial and parasitic infections responsible for GI symptoms.
Pancreatic Enzymes: Blood tests measuring the levels of pancreatic enzymes amylase and lipase help assess pancreatic function. Elevated levels are indicative of pancreatic inflammation (pancreatitis).
Liver Function Tests: High levels of liver enzymes in the bloodstream, such as ALT, AST, and ALP, can indicate problems within the liver, gallbladder, and bile ducts.
Celiac Antibody Tests: A comprehensive serum celiac profile includes multiple antibody markers associated with celiac disease. To increase this test's accuracy, the patient should be eating a gluten-containing diet and have normal total IgA levels.
SIBO Test: SIBO can be diagnosed with a breath test, which involves a series of at-home breath collections. Elevated hydrogen, hydrogen sulfide, or methane gas levels in the breath samples indicate bacterial or methanogen overgrowth.

A micronutrient test is a comprehensive nutritional panel that can assess nutritional status and diagnose nutrient deficiencies, including those commonly seen in patients with steatorrhea:

Step 3: Imaging Studies

Imaging studies can evaluate the pancreas, liver, and gallbladder.

Imaging studies may reveal the following findings in chronic pancreatitis (2):

X-Ray: pancreatic calcifications
CT or MRI: pancreatic calcifications and dilation (enlargement) of the pancreatic ducts

Liver ultrasound is a safe and noninvasive method to screen for liver disorders. Abnormal findings may include fatty infiltration, enlargement, scarring, and masses.

Step 4: Endoscopic Procedures

Some GI conditions, such as Crohn's disease and celiac disease, require endoscopic procedures for definitive diagnosis. This will require a referral to a gastroenterologist. During an endoscopy, the performing doctor inserts a long, thin camera into the mouth to visualize the esophagus, stomach, and upper portion of the small intestine. (2)

Treatment of Steatorrhea

Treatment for steatorrhea will depend on the cause and severity of symptoms. Examples include:

Pancreatic enzyme replacement therapy (PERT) is the primary treatment for EPI and involves taking pancreatic enzymes lipase, protease, and amylase with meals to support digestion
Antibiotics, either prescription or herbal, are prescribed to eradicate SIBO
Strict adherence to a lifelong gluten-free diet is the only treatment for celiac disease.
Ursodeoxycholic acid (a bile acid) is the first-line treatment of choice for primary biliary cholangitis

Dietary Management

Treatment of steatorrhea should also include education on appropriate dietary modifications.

For short-term or temporary causes of steatorrhea, such as infection, a low-fat diet can help reduce the amount of undigested fat reaching the stool. Limiting high-fiber foods can also be beneficial, as high-fiber diets tend to exacerbate symptoms of steatorrhea. The following foods could be reduced or avoided during this elimination period:

Whole nuts
Red meat
Butter, shortening, and lard
Coconut and palm oil
Fried foods

However, for chronic steatorrhea, caused by conditions like EPI or celiac disease, a prolonged low-fat diet is not ideal, as it can increase the risk of malnutrition and unintended weight loss (2). In these cases, patients should actually be encouraged to incorporate healthy fats into their diet, including:

Fatty fish (e.g., salmon, tuna, mackerel, sardines)
Nuts and seeds
Avocados
Olive oil

Patients may also have an increased requirement for fat-soluble vitamins, necessitating the need for dietary supplements or emphasizing the following foods in their diet:

Fish, beef liver, and carrots for Vitamin A

Cod liver oil, mushrooms, and fortified milk for Vitamin D
Sunflower seeds and almonds for Vitamin E
Dark leafy green vegetables for Vitamin K

Complications and Prognosis

If steatorrhea is left untreated, it can lead to several serious complications. Malnutrition is a major concern because the body cannot absorb essential nutrients effectively (2). This often results in deficiencies of fat-soluble vitamins A, D, E, and K. These deficiencies are associated with various health issues, such as vision problems, poor blood clotting, and osteoporosis.

The long-term prognosis for patients with steatorrhea largely depends on the underlying cause of the condition. Treating the root issue can significantly improve symptoms and overall health. Steatorrhea due to cystic fibrosis and primary biliary cholangitis have poorer prognoses due to the progressive nature of these health conditions. The best way to improve the prognosis of steatorrhea is to follow your doctor's recommendations and stay up-to-date with regular follow-ups with your multidisciplinary healthcare team. (2)