Trypsin & Chymotrypsin Test: What It Is & Why It's Performed

The pancreas releases the substances trypsin and chymotrypsin during normal digestion, according to the website Medline Plus. A test can reveal shortages of these substances when performed on collected stool samples.

Purpose

• Doctors perform the noninvasive test for trypsin/chymotrypsin on newborns or infants who display symptoms of cystic fibrosis, which is a mutation in the chromosome 7 gene. The test is also performed on both children and adults to determine possible pancreatic insufficiency according to the website Lab Tests Online.

Preparation

• A physician monitoring a person's pancreas may prescribe vitamin supplements and oral enzymes to address simple pancreatic issues according to the website Lab Tests Online. However, in more severe cases a physician may order a trypsin test be performed and will provide the appropriate supplies to collect a stool sample and instruct the individual of the use of such. This collection is performed in numerous ways depending on the age of the individual being tested.

Collection

• Held in place by the toilet seat, plastic wrap loosely placed over a toilet bowl catches stool, which can then be transferred to a clean container for testing, according to the website Medline Plus. Some test kits supply special tissues for the transfer of the sample from wrap to clean container. With diaper-wearing infants, place the wrap appropriately to avoid mixing the urine and feces.

Procedure

• The test involves placing a drop of emulsified feces on a thin layer of gelatin, according to the website Medline Plus. The gelatin dissolves when digested by the trypsin or chymotrypsin present in the feces.

Results

• A normal result indicates the presence of trypsin and chymotrypsin in the stool. Although not diagnostic, a negative result may indicate the need for further testing. An abnormal trypsin test is indicative of a pancreas that is not working properly. At this point, the physician may order other tests to get a more definitive diagnosis of the pancreatic problem.