Celiac disease is a digestive and immune disorder that can keep the body from absorbing necessary nutrients. "Our conception and awareness of celiac disease has evolved over the past few decades, but there are still aspects that remain poorly understood," says Dr. Ciaran Kelly, medical director of the Celiac Center at Beth Israel Deaconess Medical Center and professor of medicine at Harvard Medical School.

Perhaps not surprisingly, misconceptions are widespread among the general public. One example? Many people assume that everyone who has celiac disease is plagued by abdominal pain, bloating, or diarrhea. But actually, many adults newly diagnosed with this inherited gluten intolerance don't have these symptoms.

What's more, gluten — the sticky protein found in grains such as wheat, barley, and rye — can cause gastrointestinal distress and other symptoms in people who don't have celiac disease. Read on for a deeper dive into four myths and facts about celiac disease and related digestive conditions.

Not typically. While celiac disease can develop any time after a baby's first exposure to gluten, it's usually diagnosed much later in life. According to the National Celiac Association, the average age of diagnosis is between 46 and 56. Around 25% of people are diagnosed after age 60.

Celiac disease is slightly more common in women and among people with other autoimmune conditions, including type 1 diabetes, Hashimoto's thyroiditis (a common cause of low thyroid levels), and dermatitis herpetiformis (a rare condition marked by an itchy, blistering rash).

"We don't know why some people go from being susceptible to actually having celiac disease," says Dr. Kelly. The prevailing theory is that some sort of physical or emotional stress — such as a viral infection, surgery, or anxiety from a stressful life event — may "flip the switch" and cause the disease to appear, he says. "Increasing numbers of people are being diagnosed at midlife and older, often after they're found to have conditions such as anemia or osteoporosis caused by nutrient deficiencies," says Dr. Kelly.

When people have celiac disease, eating gluten triggers an immune system attack that can ravage the lining of the small intestine. A healthy small intestine is lined with fingerlike projections, called villi, that absorb nutrients. In celiac disease, the immune system attacks the villi, causing them to flatten and become inflamed — and thus unable to adequately absorb nutrients.

While gastrointestinal problems can occur, they aren't always present. In fact, celiac disease can present with many different symptoms that affect the nervous, endocrine, and skeletal systems. A few examples are brain fog, changes in menstrual periods, or muscle and joint pain.

If you feel sick after eating gluten, you probably have celiac disease, right? Actually, that may not be true. Some people have non-celiac gluten sensitivity (also called gluten intolerance), which can cause uncomfortable digestive symptoms after eating gluten. But gluten intolerance differs from celiac disease.

"Non-celiac gluten sensitivity appears to be a real phenomenon, but it's not well defined," says Dr. Kelly. It's unclear whether people experiencing it are intolerant to gluten or to something else in gluten-containing foods.

The sole treatment for celiac disease — adopting a diet that avoids all gluten-containing foods — doesn't always help. This problem is known as nonresponsive celiac disease.

"About 20% of people with celiac disease have ongoing symptoms, despite their best efforts to stick to a gluten-free diet," says Dr. Kelly. Others have intermittent signs and symptoms, particularly when they are accidentally exposed to gluten. Accidental exposures often happen when people eat prepared or restaurant foods that claim to be gluten-free but are not. Cross contamination with gluten-containing foods is another potential route.

Potential solutions to nonresponsive celiac disease are being studied. Three promising approaches are:

Harvard Health Publishing

School vacation coming up? Wondering how to spend that time? Given how tiring holidays can be — especially for parents who are working — it's understandable why children are often allowed to spend hours with the TV, tablet, or video games. After all, happy, quiet kids make for happy parents who can finally get stuff done — or relax.

Except kids are spending way too much time in front of screens. According to the American Academy of Child and Adolescent Psychiatry, kids ages 8 to 12 are spending four to six hours a day watching or using screens — and tweens and teens are spending nine hours.

Given how enticing devices and social media can be, those numbers can easily go higher during unscheduled times like weekends and school vacation. That's why it's good to be proactive and come up with other activities. Below are some ideas for parents and caregivers to try. These are mostly good for kids through elementary school, but tweens and teens may enjoy some of them too.

Go outside. This sounds obvious, but spending time outdoors is something kids do less than they used to — and it can be really fun. If you have a yard, go out into it and play hide-and-seek or build a fort from snow or anything else that's around. If you don't have a yard, go to a local park or just go for a walk. A scavenger hunt up and down the block or game of I Spy may be a good enticement.

Go to the library. Do this early on in vacation, so that your child has lots of books, puzzles, and games to pass the time. Check out as many as they allow and you can carry. Ask if a Library of Things is available at a branch near you: crafts, tools, musical instruments, birding kits, telescopes — even metal detectors may be checked out for free.

Build a fort in the living room. Use blankets or sheets over chairs; if you have a small tent, set it up. Bring in pillows, sleeping bags, and flashlights; let the kids sleep in it at night. Let it stay up all vacation.

Build a city in the living room. Use blocks, Legos, boxes (or anything else), and add roads, cars, people, animals, trains, and other toys. Let it stay up all vacation, and make it bigger every day.

Get creative. Go to the craft store and stock up on inexpensive supplies. Buy things like poster board, huge pieces of paper (you could use those for your city, too, to make parks, roads, and parking lots), paints, and markers. You can make a paper mural, a comic book, a story, posters, or whatever catches your child's imagination. If you know how to knit or sew, think about teaching your child or making a simple project together.  Play music while you create.

Read out loud. There are so many books that are fun to read aloud. When my children were younger, we read the Harry Potter series out loud, as well as the Chronicles of Narnia and books by E.B. White and Roald Dahl. Act out the voices. Have some fun.

Have a puppet show. If you don't have puppets, you can make some with socks — or you can hold up dolls or action figures and do the talking for them. You can make a makeshift stage by cutting out the back of a box and taping cloth (like a pillowcase) to fall over the front.

Get out the games. There are so many that work across the ages, like checkers, chess, Uno, Connect 4, Sorry, Twister, Clue, Scrabble, or Monopoly. We forget how much fun these can be.

Bake. You don't have to get fancy — it's fine to use mixes or pre-made cookie dough. There's nothing better than baked goods straight from the oven, and adding frosting and decorations makes it even more fun. Turn on music and dance while things bake.

While parents or caregivers need to be involved with some of these activities (like the ones involving the oven, or reading out loud), kids can do many of them independently once you have it started. Which, really, is what children need: time to use their imagination and just play.

But you just may find that once you have things started, you'll want to play, too.

Harvard Health Publishing