Medical Information

Printable Testing Reference Sheet

Proper testing for celiac disease is important before starting a gluten-free diet.

It is strongly recommended to test for celiac antibodies prior to starting a gluten-free diet.

Celiac disease is a serious autoimmune condition and a definitive diagnosis is essential. If a gluten-free diet is started before diagnosis, tests for celiac disease can be unreliable and can show a false negative.

The gluten-free diet is not a trivial undertaking. It requires lifestyle changes and a whole new set of skill dealing with every aspect of food. Without a firm diagnosis, it is difficult to commit to a lifelong gluten free diet. As people feel better, it is becomes easier to either give up on the diet or cheat occasionally. People with undiagnosed celiac disease are damaging their bodies each time gluten is consumed.

If testing is positive, then a lifelong gluten-free diet is currently the only option. If testing is negative, a gluten-free diet may be very helpful in alleviating symptoms, but the same level of commitment is not necessary.

Step One: Blood Test

Recommended Tests

Blood tests are the first step in a diagnosis of celiac disease.  A doctor will order one or more of a series of blood tests to measure your body’s response to gluten

Currently, recommended tests include:

Total IgA
IgA – tTG
If IgA is deficient, it is recommended that the IgG/IgA-DGP also be ordered.  At the discretion of the doctor, IgG-AGA can also be ordered.

It is important to continue eating normal, gluten-containing diet before being tested for celiac disease. Do not start a gluten-free diet before being tested for celiac disease.  If the blood tests and symptoms indicate celiac disease, a physician will likely suggest a biopsy of the lining of the small intestine to confirm the diagnosis.  Keep in mind that going gluten-free before being tested for celiac disease can prevent diagnosis.  However, people who have already adopted the gluten-free diet without having been tested for celiac disease can undergo a “gluten challenge” in order to receive accurate test results.

Printable Testing Reference Sheet

Step Two:  Endoscopy

To confirm a celiac disease diagnosis, your doctor may recommend an upper gastrointestinal endoscopy. This procedure will allow your doctor to identify any inflammation or damage in your small intestines, which is a sure sign of celiac disease. Your doctor will take a small biopsy of your intestines during the endoscopy, which will help to confirm your diagnosis. In order for the endoscopy to be accurate, the patient must be on a gluten-containing diet.

An endoscopy may sound like a big procedure, but it only takes about 15 minutes and is a low-risk procedure

Why It’s Recommended

While blood tests are helpful in diagnosing celiac disease, they aren’t perfect.  False negatives and false positives are possible, so an endoscopy is needed.

In the small intestine, there are fingerlike projections called “villi” that help you absorb nutrients. In individuals with celiac disease, gluten damages the villi and causes them to flatten. As a result, the body can’t get the nutrients it needs, which leads to many of the health problems associated with celiac disease. With a biopsy, doctors can see if the villi are flattened.

Endoscopy has long been known as the “gold standard” for celiac disease diagnosis. As blood testing improves, endoscopy may be needed less and less, but for now it remains essential.


The actual procedure does not take long, but you will need to take some time to properly prepare. Your doctor will give you a full set of instructions to follow in preparation for the endoscopy, and certain instructions will be dependent upon your age. Here are some brief details of what you can expect.

You will be asked to fast (no food or drink) for 6-8 hours before your endoscopy. This will ensure that your stomach is empty for the procedure. You may also be asked to stop taking certain medications, such as anti-clotting drugs, for a certain period of time before the procedure.

Before the endoscopy begins, you will be sedated and the amount and type of sedation will depend on your age and any other co-existing medical conditions. Sometimes you will be given an anesthetic to numb your throat in addition to the sedative. You will be asked to lie on your back or on your side for the procedure.

During the Endoscopy

During the endoscopy, your doctor will snake a very thin tube through your mouth. When the tube reaches your small intestine, a small tool will be used to take four to eight biopsies from your intestinal wall. After the procedure, a pathologist will use a microscope to examine the extent of damage to the villi. If your villi appear flattened or damaged, it is likely that celiac disease is the cause.

After the Endoscopy

Following the procedure, you will be transferred to a recovery room until any medication or sedative wears off. You may have a mild sore throat or feel slightly bloated as a result of the procedure, but those sensations usually clear up quickly. Most individuals are able to resume eating food within a few hours, after they are fully recovered.


Often, doctors are able to view the image results of an endoscopy that day. But in the case of celiac disease, it’s the actual biopsy results that your physician is most interested in. Therefore, you may be asked to schedule an appointment to go over the results at a later date since it may take a few days for the pathology department to return the biopsy results to your physician.

Positive Test Result:

If you test positive for celiac disease, you will need to manage a strict gluten-free diet.

Negative Test Result: 

If your small intestinal biopsy results indicate that celiac disease is not present, but you and your doctor still suspect gluten is the cause of your symptoms, you may want to explore the possibility of non-celiac gluten sensitivity (‘gluten sensitivity’).

Potential celiac disease is also an option. This is a term used when an individual has a positive celiac disease blood test but a normal small intestinal biopsy. People with potential celiac disease are at an increased risk for developing celiac disease as indicated by positive celiac disease blood tests. This means that they may transition into developing active celiac disease, which is marked by intestinal damage.

At this time, there are no universal guidelines on treating potential celiac disease with a gluten-free diet and most physicians recommend continuing with a regular gluten-containing diet.

Because active celiac disease may develop over time, it is important for individuals with potential celiac disease to monitor any changes in their health such as new signs or symptoms that may indicate celiac disease.

Talk to your doctor about other reasons for your negative biopsy test results and what, if any, future follow-up tests are recommended for you.

Local Medical Practitioners 

Singapore based Gastroenterologists with experience in Celiac Disease
(details correct October 2017)


★ Dr. Brian Schwender  MD, FASGE, FAMS (Gastroenterology)
Novena Specialist Center
8 Sinaran Drive, Suite 04-01 & 04-03, Singapore 307470
Tel +65 6659 6918,
Tucker Medical Website

Dr HY Wong
Gastrointestinal & Liver Specialist Clinic
3 Mount Elizabeth #07-10, Singapore 228510
tel: 62358002, email:

Assoc. Prof Reuben KM Wong
Visiting Consultant Gastroenterologist – National University Health System, Consultant Gastroenterologist
gutCARE Digestive, Liver, Endsocopy Associates
Mount Elizabeth Novena Specialist Centre, Singapore 329563
tel +65 6734 3435,  website

Prof Gwee KA
Consultant Gastroenterologist (Gleneagles Hospital)
Adjunct Associate Professor of Medicine (National University of Singapore), Stomach Liver & Bowel Clinic
6A Napier Road 05-37, Gleneagles Annexe Block, SG 258500
tel +65 6474 6848, website

Dr CM Yeo
Consultant Gastroenterologist, Gastroenterologist & Liver Specialist Clinic, Mount Elizabeth Novena Specialist Centre
38 Irrawaddy Road 11-57, Singapore 329563
tel: +65 6694 6968, email:


Dr Nancy Tan
Consultant Paediatrician
Gastroenterology, Hepatology and Nutrition
SBCC Baby & Child Clinic Gleneagles Medical Centre
09-05 Napier Road, Singapore, tel: +65 6235 6706
email:,   website

Assoc. Professor Marion Aw Hui Yong
Senior Consultant, Division of Paediatric Gastroenterology, Hepatology and Nutrition
Khoo Teck Puat – National University Children’s Medical Institute,  National University Hospital
tel +65 6772 4420, email:  website

Local Dietitians Specializing in Celiac Disease

Bridget Marr, Registered Dietitian and Nutritionist
Nutritional Solutions
Office:  + 65 9665 3081

Karen Wright, Registered Dietitian with a special interest in paediatrics and allergy
Office: 96610187
2017-10-15T21:47:40+00:00 October 15th, 2017|