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Trypsin/Chymotrypsin (Stool)

Does this test have other names?

Test for concentration of pancreatic enzymes, direct pancreatic enzyme measurement

What is this test?

This test checks your stool sample for trypsin and chymotrypsin, two enzymes made by the pancreas. The test measures how well your pancreas is working if you have cystic fibrosis (CF).

CF stops the pancreas from making its normal digestive enzymes. In most cases, this problem shows up during the first years of life.

Children with CF often have trouble absorbing nutrients from their food. They may not put on weight and grow normally. Most people with CF live into their 20s and 30s, but this requires proper medical care such as treatments for lung problems and replacement pancreatic enzymes to help with digestion.

Based on the results from this test, your healthcare provider may prescribe replacement pancreatic enzymes. 

Why do I need this test?

You may need this test if you have CF and your healthcare provider suspects that your pancreas isn't working the way it should. Signs and symptoms that may mean your pancreas is not working properly include:

  • Belly (abdominal) pain

  • Weight loss, because you don’t have the enzymes you need to help digest food

  • Nausea

  • Vomiting

  • Diarrhea

  • Low blood pressure

  • Rapid heartbeat

  • Recurrent pancreatitis

  • Recurrent sinusitis

  • Male infertility

What other tests might I have along with this test?

Your healthcare provider may order other tests to look at how your pancreas is working. These include:

  • Elastase and fat. Elastase is an enzyme that breaks down protein. Low levels of elastase or high levels of fat in your stool mean that you may have a problem with your pancreas.

  • Pancreatic function. Your provider will stimulate your pancreas to make fluid and then collect it from your small intestine.

What do my test results mean?

Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your healthcare provider.

Abnormal levels of trypsin or chymotrypsin mean that your pancreas isn't working properly.

How is this test done?

This test requires a stool sample. Your healthcare provider may ask you to collect a single stool sample or all of your bowel movements during a 72-hour period.

Does this test pose any risks?

This test poses no known risks.  

What might affect my test results?

Other factors aren't likely to affect your results.

How do I get ready for this test?

You don't need to prepare for this test. But be sure your healthcare provider knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use. 

Medical Reviewers:

  • Moloney Johns, Amanda, PA-C, MPAS, BBA
  • Walton-Ziegler, Olivia, MS, PA-C