• Also Known As:
  • Chymotrypsin
  • fecal
  • Formal Name:
  • Stool Chymotrypsin
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At a Glance

Why Get Tested?

To help detect and evaluate pancreatic insufficiency

When To Get Tested?

When you have symptoms such as persistent diarrhea; foul-smelling, bulky, greasy stools; malnutrition; malabsorption; and vitamin deficiency and pancreatic insufficiency is suspected

Sample Required?

A fresh stool sample, uncontaminated with urine

Test Preparation Needed?

If you are taking pancreatic enzymes, you may be instructed to discontinue taking the enzymes 5 days before providing the stool sample.

What is being tested?

Chymotrypsin is an enzyme that digests protein in the small intestine. This test measures the amount of chymotrypsin in stool to help evaluate whether your pancreas is functioning properly.

Chymotrypsinogen, the inactive precursor of chymotrypsin, is produced in the pancreas and transported to the small intestine. In the small intestine, it is activated to form chymotrypsin. It is one of the enzymes responsible for breaking down the protein in food into smaller pieces, called peptides. Chymotrypsin is detectable in the stool if the pancreas is functioning normally.

Individuals with pancreatic dysfunction may either have blocked pancreatic ducts or the cells that produce chymotrypsinogen may be damaged or destroyed. Such cell damage and duct blockage cause pancreatic insufficiency because the amount of enzymes transported to the small intestine is inadequate for proper food digestion. This is often seen in conditions such as chronic pancreatitis and sometimes pancreatic cancer.

Common Questions

How is the test used?

The chymotrypsin test is used along with other tests, such as a fecal fat and/or fecal elastase, to evaluate both children and adults for pancreatic insufficiency.

Pancreatic insufficiency occurs when the pancreas cannot produce and/or transport enough digestive enzymes to break down food in the intestine and aid in the absorption of nutrients. It typically occurs as a result of progressive pancreatic damage.

When is it ordered?

A chymotrypsin test may be ordered when you have signs and symptoms of pancreatic insufficiency, such as:

  • Persistent diarrhea
  • Abdominal cramps
  • Weight loss
  • Foul-smelling, bulky, greasy stools
  • Malnutrition
  • Malabsorption
  • Vitamin deficiency
  • In children, an inability to gain weight, delayed growth

What does the test result mean?

A positive result, indicating the presence of chymotrypsin in the stool, is normal. Chymotrypsin is present in the stool of healthy individuals.

A negative result may mean that you have pancreatic insufficiency. A negative result is not diagnostic, but it does indicate that further testing may be needed.

What other laboratory tests might be done if I or my child has a negative cymotrypsin test?

Your health care provider may order a stool test for fecal fat or fecal elastase or a blood test for amylase or lipase to look at other aspects of pancreas and digestive function.

What causes pancreatic insufficiency?

Pancreatic insufficiency can be caused by repeated bouts of acute pancreatitis or by chronic pancreatitis. It is less frequently but sometimes associated with pancreatic cancer. Other causes of insufficiency may include celiac disease, Crohn disease, autoimmune pancreatitis (immunoglobulin G4-related disease), Zollinger-Ellison syndrome, and some surgical procedures that can lead to a decrease in gastrointestinal or pancreatic function.

Additionally, people who are carriers of a mutation in the CFTR gene may have pancreatic insufficiency and experience the associated signs and symptoms.

In children, pancreatic insufficiency is most frequently associated with cystic fibrosis (CF) or Shwachman-Diamond Syndrome (SDS). SDS is the second most common cause of inherited pancreatic insufficiency, after CF. All those with SDS have some degree of pancreatic insufficiency beginning in infancy.

Is there anything else I should know?

The stool elastase test has better diagnostic utility compared to fecal chymotrypsin.

If your pancreas is not functioning properly, you will need to be monitored closely by your health care provider. You may be prescribed oral enzymes and vitamin supplements to relieve symptoms and to improve your nutrition.

View Sources

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2020 review performed by Uvaraj Uddayasankar, PhD, FCACB, Clinical Biochemist, LifeLabs ON.

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