Chymotrypsin in Stool

This test measures the amount of chymotrypsin in a stool (poop) sample. Chymotrypsin is an enzyme, a protein that speeds up certain chemical reactions in your body. It is released by your pancreas (an organ behind your stomach) to help break down the protein in your food during digestion.

If your pancreas is working as it should, there will be some chymotrypsin in your stool sample. However, if your pancreas is releasing lower-than-normal amounts of chymotrypsin, you may not have enough enzymes to digest your food properly. This is a condition known as exocrine pancreatic insufficiency.

It's often called pancreatic insufficiency or EPI for short. Pancreatic insufficiency is most often caused by chronic pancreatitis, inflammation of the pancreas. It may also be caused by cystic fibrosis (CF), a genetic disorder that causes mucus to build up in your lungs and other organs, including the pancreas.

People with CF often have trouble absorbing nutrients from food. Your stool sample may also be tested for trypsin. This is another enzyme that is released by the pancreas and helps with digestion.

Why this test is done

You may need this test if you have symptoms of a pancreatic insufficiency. These include:

• Chronic diarrhea
• Abdominal (belly) pain
• Bloating and gas
• Loose, foul-smelling, greasy stools
• Weight loss

How to prepare

You may need to stop taking certain medicines before this test, such as if you are taking pancreatic enzymes, so tell your provider about everything you take. But don't stop taking any medicines unless your provider tells you to.

Sample type

Stool

Other names for this test

fecal chymotrypsin, trypsin and chymotrypsin stool test