Tuesday, May 1, 2012

Breath Hydrogen Test

The only test for Fructose Malabsorption is a breath hydrogen test.  At this time there is no other way to see if a person has FM, other then by an elimination diet.  While an elimination diet is ultimately going to decide if you are on the right track, sometimes it helps to just know that you have a confirmed diagnosis.  During the beginning of our FM journey it was good to know that there was positive tests for each of us.  When we were confused or frustrated or just wanted to throw out he whole idea of a low fructose diet as we weren’t getting the results we had hoped for a quick as we had hoped for it helped to know that the tests had come back positive and we had to work through these down times.  There were times where we questioned if it was truly a FM problem, but knowing the test was positive meant we had to buckle down and be faithful to a low-fructose diet in order to determine if there were other issues as well.

In Canada there is not an issue over the cost of having the test done since we are covered by the government for such tests.  The issue is usually where to get such a test done.  Our family had the testing done at the GI Investigation Clinic in the McMaster University Hospital in Hamilton.  It would be great if those who have had testing done, whether Canadian or elsewhere, would leave a comment stating where you had it done so others are able to find a lo cation near them to get the testing done. 

The Breath Hydrogen Test (BHT) for Fructose Malabsorption is done the same way as a BHT for lactose intolerance, SIBO and sucrose intolerance.  This test measures the amount of hydrogen in your breath.  Hydrogen gas is produced from intestinal bacteria.  The bacteria produce hydrogen when they are exposed to unabsorbed food, particularly sugars and carbohydrates.  Large amounts of hydrogen may be produced when a person has a problem with the digestion or absorption of food in the small intestine, which in turn allows unabsorbed food to reach the colon.  Some of this hydrogen is absorbed into the blood flowing through the wall of the small intestine and colon. This hydrogen containing blood travels to the lungs when the hydrogen is released and exhaled in normal breathing.  There are studies suggesting that some patients do not produce hydrogen but methane and so some tests are now testing for both hydrogen and methane. I have not read much about this so I cannot comment further on this.BHT

When a person goes for a BHT they will be required to follow a strict diet the day before coming in for the test and fast for 12 hours before the test.  I do not remember the details of the diet the day before but I believe it had to do with not eating whole grains or high fiber foods.  The test involved blowing into a bag every 15 minutes for 2-3 hours. 

When you arrive for the test they will first take a breath sample to determine your base line.  You will then be required to drink a solution of fructose.  After that your breath sample will be taken every 15 minutes.  The picture shows a sample of how the breath is taken.  You will put the blue part to your mouth and blow hard into the bag.  The sample is removed from the bag with the syringe, allowing the bag to be used again for the next sample.  During the test it is important to write down or report any symptoms you have that are typical to the reason you came for the test. 

A diagnosis is made by evaluating the pattern the hydrogen takes after the sugar is digested.  The amount of gas produced determines how well the sugar was absorbed.  The more gas produced the less sugar absorbed.  If the level of hydrogen rises higher then 20 ppm (parts per million) from the baseline test a person is considered to have FM.  (For methane producersif the number rises 12ppm then you are considered to have FM)

BHTing can also be done on young children.  Our son, Matthew, was sixteen months old when he had his test done.  The thing I dreaded most for his test was getting him through the fasting stage.  He did surprisingly well. The other challenge is to get a child to drink the solution, and to drink it all quickly.  For Matthew it worked out fine that he was not particular about what was in his bottle as long as he could have something to drink.  So we pour the solution in his bottle IMG_9202_3_1and it went down quickly. 

Because young children can not blow hard enough into the bag for collecting samples, they instead place a mask over their face and have them breath into this mask.  You can see Matthew having a collection taken in this picture.  I was amazed how well he cooperated that day.  I did not expect things to go that well.  It’s difficult to put your child through a test but in the end we had a positive result and knew what we were working with.  It’s also very difficult to play guessing games with a small child.  In his case we would have given up on the FM idea if we did not have a positive test at the time.  It took us another 8 months before we were able to figure out that Matthew is also intolerant to rice.  We persevered with the low-fructose diet because we knew that he had tested positive and that initially he had done better once fructose was removed.  At 16 months Matthew did not eat any solids but strictly drank a bottle … he refused to eat.  We removed him from the formula he was on when we found out he had FM.  He was on a hypo-allergenic formula because he did not tolerate milk or soy.  We started with trying to put him back on milk, which failed, next we tried soy, which failed.  So we moved on to rice milk. He had a diet filled with rice – rice milk, rice for meals, rice flour – (he had been on a gluten free diet since young) – no wonder his poor tummy was so upset.  Matthew was two years old before he began to truly eat solid foods, that was after we removed rice from his diet.  Over the next few months his tummy began to heal and his eating took off.  Hard to believe now that we had so much trouble in the beginning.


  1. Were you able to find a place that did the test.. tell them you wanted it done and then have it done when you got there? Or did you have to meet with a doctor and they refer you to have one done.. like they say they think you should have one done?

    1. I had my testing done at McMaster University Hospital in Hamilton, Ontario. I had to get a referral from a doctor to get the test done. For myself it was just a matter of asking my doctor for the requisition as my daughter and son had already been diagnosed. I'm not sure if there is any other way to have it done in our area as in Canada tests are done through doctors since it is covered by the government. If there are others in parts of Canada where this is done differently or who know if there is others ways to get it done it would be great to hear about it, but since we do not have privatized care I am not aware if there is another way to have the testing done.

      I do know that in the US there are different way to get the testing done, but since I am not from the US I would not be able to provide more information regarding that. If you do need more information it would be best to go to the Fructose Malabsorption Support Group and ask if there is anyone who can help you with this information based on the area you are in.

  2. I had my test done at UCLA Medical Center in California (VERY positive for FM). I was sent for the test by a gastroenterologist. I actually had a super strong reaction to a diluted version of the solution (fructose mixed with glucose)

  3. First off, thank you for putting up this blog. Just wondering where your doctor send the referral to. I know you named the Hospital, but anything specific like the name of the lab or name of doctor. Thanks in advance.

  4. Thank you for your wonderful blog! I wanted to mention that I had a false negative FM hydrogen test but a positive FM methane test. A fairly large percentage of fructose malabsorbers have a false negative for the hydrogen test because of methane producing bacteria, so it is important to note that the hydrogen test is not the only diagnostic.