Trypsin and chymotrypsin are substances released from the pancreas during normal digestion. When the pancreas does not produce enough trypsin and chymotrypsin, smaller-than-normal amounts can be seen in a stool sample.
This article discusses the test to measure trypsin and chymotrypsin in stool.
Stool - trypsin and chymotrypsin
How the test is performed
There are many ways to collect the samples. Your health care provider will tell you how to collect the stool.
You can catch the stool on plastic wrap that is loosely placed over the toilet bowl and held in place by the toilet seat. Then put the sample in a clean container. One type of test kit contains a special tissue that you use to collect the sample. Then you put the sample in a clean container.
Infants and young children:
For children wearing diapers, you can line the diaper with plastic wrap. The plastic wrap should be placed so that urine and stool do not mix.
A drop of stool is placed on a thin layer of gelatin. If trypsin or chymotrypsin are present, the gelatin will clear.
How to prepare for the test
Your health care provider will provide you with the supplies needed to collect the stool.
Why the test is performed
These tests are simple ways of finding out whether you have a decrease in pancreas function. This is most often due to chronic pancreatitis.
These tests are most often done in young children who are thought to have cystic fibrosis.
Note: This test is used as a screening tool for cystic fibrosis but it does not diagnose cystic fibrosis. Other tests are needed to confirm a diagnosis of cystic fibrosis.
The result is normal if there is a normal amount of trypsin or chymotrypsin in the stool.
What abnormal results mean
An abnormal result means the trypsin or chymotrypsin levels in your stool are below the normal range. This may mean that your pancreas is not working properly. Other tests may be done to confirm that there is a problem with your pancreas.
Forsmark C. Chronic pancreatitis. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisinger and Fordtran's Gastrointestinal and Liver Disease. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2010:chap 59.
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and George F. Longstreth, MD, Department of Gastroenterology, Kaiser Permanente Medical Care Program San Diego, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.