What Are the Signs of Sugar Intolerance in a Baby or Toddler?

What Are the Signs of Sugar Intolerance in a Baby or Toddler?

Chronic diarrhea, gas, and even diaper rash could be due to Sucrose Intolerance caused by CSID. This rare disease, informally referred to as “Sugar Intolerance,” is often mistaken for common conditions with the same symptoms.

Signs and Symptoms of CSID

All babies spit up. It’s their go-to move. Tots are also known for producing some room-clearing gas, and most have had a couple of bouts of diarrhea each year before they turn 5-years-old.

And let’s not forget the vomiting episodes that will surely make you recall scenes from “The Exorcist.” Such are the many messy joys of parenthood.

But if you’ve noticed that your baby or toddler always seems to have some kind of belly problem and, more importantly, that seems to defy all treatment, then your child may have a type of Sucrose (sugar) Intolerance caused by Congenital Sucrase-Isomaltase Deficiency (CSID).

What Is Sugar Intolerance?

You’ve probably heard of lactose intolerance, which makes some people unable to eat cheese or ice cream or drink milk. That’s because their bodies don’t make enough of the enzyme, lactase, a chemical that helps digest the sugar found specifically in dairy foods.

Sugar Intolerance is very similar. In this case, your child lacks the function of the enzymes sucrase and isomaltase, which are needed to help digest some sugars and starches.

While babies with CSID have the deficiency at birth (because it’s a genetic, or inherited, condition), symptoms only start showing up once they reach four to six months.

Why is that the magic date? Because that’s typically the time when you start introducing solid foods, typically cereals, fruits, and vegetables, which are high in sugars and starches.

“When the body can’t break down sugar, it enters the colon where bacteria feed off it, and fermentation begins. That causes gas and diarrhea,” explains Joseph F. Fitzgerald, MD, pediatric gastroenterologist at Riley Hospital for Children in Indianapolis, Indiana.

No wonder babies are so cranky!

A Frustrating Diagnosis

For most tots, diarrhea and vomiting are simply the all-too-common result of bumping into one of the many viruses that bedevil childhood.

So, how do you know if your baby’s belly battles are run-of-the-mill kid ailments or a super-rare genetic disorder?

It’s a bit of a sticky wicket. With common symptoms like irritability, belly pain, gassiness, bloating, diarrhea, vomiting, and diaper rash, even the medical experts find CSID tricky to diagnose.

These copycat CSID symptoms point to a host of more common stomach problems, like food allergies, irritable bowel syndrome, gastroenteritis (stomach inflammation or infection), celiac disease (gluten intolerance), and lactose intolerance.

CSID is so rare, pediatricians just don’t see that many cases, so it’s often not on their radar. A recent, large study found that slightly more than 9% of children in the United States, who were tested by a doctor due to GI complaints, had low sucrase function.1 Even among patients with GI complaints, the prevalence is less than 9%.

“CSID takes time to diagnose because it’s not one of the first two, three, or four things that we think of when we see children with these symptoms,” says Raza A. Patel, MD, MPH, pediatric gastroenterologist in Salt Lake City, Utah.

Going to a specialist called a pediatric gastroenterologist, also called a GI doctor, may improve your chances of getting your child tested and diagnosed accurately and quickly, using new testing that is now available.

Testing! Testing! Testing!

Fortunately, if you and your pediatrician suspect CSID, there are tests that can assist in diagnosing it: genetic testing, an upper endoscopy with a biopsy of the small intestine to measure enzyme activity, and breath tests.

Children who test positive for CSID are typically referred to a registered dietitian (RD) who can start them on a restricted diet that eliminates all sugary and starchy foods, and then gradually reintroduces each food to determine which ones kids can safely eat without reacting.

An elimination diet involves tracking exactly what your child eats and the response to specific foods so that trigger foods can be identified.

“Symptoms typically start 60 to 90 minutes after sugars are consumed,” says Patel. “It depends on how sensitive the child is.”

A Range of Symptoms

Symptom severity also depends on several variables, including the level of sucrase enzyme activity they have. Those who have some sucrase enzyme activity experience milder symptoms compared to those who have none at all.

“Kids with partial sucrase enzyme deficiency may get cramps, gas, and diarrhea shortly after a meal,” says Devandra Mehta, MD, pediatric gastroenterologist at Arnold Palmer Hospital for Children in Orlando, Florida. “Sometimes there is a lot of pain. Sometimes it’s a dull pain with gas and no diarrhea.”

Sometimes kids just get so uncomfortable, they simply lose their appetite and end up feeling weak, tired, and cranky.

Layer on the social anxiety of being accused of “cutting the cheese” or never being quite sure if they’re going to poop in their pants after lunch – and the embarrassment if they do – and “kids could miss a lot of school,” says Adrian Miranda, MD, pediatric gastroenterologist at Children’s Hospital in Milwaukee, Wisconsin.

Don’t Confuse Severe Diarrhea with CSID

CSID causes chronic diarrhea, which is loose, watery poop that happens three or more times a day and lasts for at least four weeks.

But severe diarrhea is something else. Occurring as often as 10 times a day and usually lasting two to three days, it’s a huge red flag. “That can lead to dehydration and malnutrition,” explains Fitzgerald. “In infancy, this can be devastating.” Signs of dehydration include fewer wet diapers, dry lips and mouth, increased fussiness, and crying without tears.

“Very rarely is the diarrhea so severe that the child is actually losing weight,” assures Patel. “But when a child isn’t growing well, that’s when we start to worry.”

If your baby or toddler experiences severe diarrhea, see your pediatrician as soon as possible. That is most likely due to an infection or illness other than CSID.

An Individual Plan

Fortunately, once CSID is diagnosed, it can be managed through a combination of medication and diet changes.

It’s important to work with an RD who can tailor food plans to an individual child. Some kids may even be able to eat sweets.

“There seems to be a difference in sensitivity to sugars,” says Patel, who compares CSID to lactose intolerance.

“Some kids who are lactose intolerant can tolerate a certain quantity of milk, while others can tolerate very little. There seems to be the same kind of variability with CSID where, depending on how much your body is affected by its inability to process these sugars appropriately, you may have a lot of symptoms or very few. An RD can help determine which foods your child can tolerate and which ones they can’t.”

A Manageable Condition

While CSID is a lifelong condition, diet changes make it fairly easy to manage. Plus, the space for digestion in the intestines grows as children grow, so someone with mild CSID may have fewer symptoms as they age.

“We typically see that as kids get older, they can tolerate more; and their symptoms become milder,” says Fitzgerald.

Patel agrees. “CSID is extremely manageable,” he says. “There are treatments that make this a very livable disease.”

  1. Nichols BL Jr, Adams B, Roach CM, Ma CX, Baker SS. Frequency of sucrase deficiency in mucosal biopsies. J Pediatr Gastroenterol Nutr. 2012;55(suppl 2):S28-30. doi: 10.1097/01.mpg.0000421405.42386.64

Sucrose Intolerance may be more common than you think.