Congenital Sucrase-Isomaltase Deficiency (CSID) | Alaska Native Tribal Health Consortium

Congenital Sucrase-Isomaltase Deficiency (CSID)

ANTHC’s CSID Program provides education, resources, and support for patients, caregivers, and health care providers.

CSID Program
(907) 729-3628

CSID Outreach and Education Program

ANTHC’s Congenital Sucrase-Isomaltase Deficiency (CSID) Program provides education, resources, and support for patients, caregivers, and health care providers throughout Alaska. The program collaborates with Tribal Health Organizations to assist with processes for diagnosis and management of CSID. 

What Is CSID?

CSID stands for Congenital Sucrase-Isomaltase Deficiency. CSID is a genetic change a person is born with that makes it hard to digest sugar and starch. The type of sugar that is hard to digest is sucrose, also known as table sugar.

Our bodies use digestive enzymes to help break down food. The enzyme that helps break down sucrose and starch is called sucrase-isomaltase. In a person with CSID, the body may not have enough of this enzyme to break down sucrose and starch.

What are the Symptoms of CSID?

When the body cannot break down sucrose and starch, symptoms like diarrhea, bloating, and an upset stomach can occur. Symptoms can happen every time a food with sucrose and/or starch is eaten. Some people with CSID may have more severe symptoms than others. In infants, symptoms often begin when table foods are introduced around 4-6 months of age.

What Foods Contain Sucrose and Starch?

Common foods that contain sucrose include:

  • Baked goods – cookies, muffins, cakes, brownies
  • Candy
  • Jams/jellies
  • Ice cream
  • Flavored yogurt
  • Sweetened beverages, such as pop, juice cocktails, powdered drink mixes, energy and sports drinks
  • Some fruits, such as apples and oranges
  • Some vegetables, such as carrots and peas

Common sources of starch include:

  • Bananas
  • Bread
  • Cereal
  • Corn
  • Crackers
  • Oats
  • Pasta
  • Potatoes
  • Rice

This list is not all-inclusive. There are many other foods that contain sucrose and starch. See Food Guides in Resources tab.

Managing Symptoms of CSID

Symptoms of CSID can be managed by limiting foods that contain sucrose and starch. Some people with CSID may be able to tolerate starchy foods better than foods with sucrose.

A traditional Alaska Native diet is excellent for managing symptoms of CSID. Traditional foods are naturally low in sucrose and starch, and are usually well tolerated by someone with CSID. 

CSID symptoms can also be partially managed with a medication called Sucraid®. This medication contains a digestive enzyme that helps break down sucrose. It does not help break down starch. Sucraid®, in combination with diet modifications, can help control symptoms of CSID.

How Common is CSID?

The number of Alaska Native people who have CSID is not fully known. Healthcare providers have not been able to identify CSID in Alaska Native people for very long. It is estimated that 3-10 percent may have CSID.

How is CSID Diagnosed?

Your health care provider may ask you to give a blood sample to determine if you have CSID. The blood sample will be sent to an out of state lab to be analyzed. It may take 4 weeks until your provider gets the results. The blood test can be used to test children and adults.

There is also a breath test available that can be used to test people 18 years of age or older. The test requires drinking a sucrose solution and breathing into several tubes over two hours. These tubes will be sent to an out of state lab to be analyzed. It may take a week or longer for your health care provider to receive the results.


Provider Resources

Patient education materials, posters, and brochures are available, contact the CSID Program to order.

For CSID Clinical Guideline visit