Skip navigation

Calls to Action

Solving Mystery of Foul Breath in Adult with Autism and Down Syndrome

“Our 26-year-old daughter has autism and Down syndrome. The most horrible problem is her awful breath. It’s so bad, it’s hard to let her get close to us, let alone kiss us. Her dentist ruled out cavities and infections, and we’ve tried everything from mouthwash to constantly brushing her teeth and tongue. She doesn’t chew her food, but just bolts it down whole. A test for blockages found none. But it found food from the previous day still in her stomach. I asked if that could produce the horrible smell, but the doctor dismissed me. Any insights or advice would be greatly appreciated.

Editor’s note: The following information is not meant to diagnose or treat and should not take the place of consultation, as appropriate, with a qualified healthcare professional.

Today’s “Got Questions?” answer is from gastroenterologist Tim Buie. Dr. Buie practices at Massachusetts General Hospital’s Lurie Center for Autism. The center is one of 14 sites in the Autism Speaks Autism Treatment Network.

Thank you for reaching out with your question.

From your story, I see several possibilities to consider. It sounds like a swallowing evaluation showed no blockage. This same study should have shown whether there was a collection of material stuck in the stomach. We call this a bezoar. On an X-ray, this could well look like retained food in the stomach. The difference with a bezoar is that the stomach never fully empties this material. So something may be stuck, or blocked, after all.

To investigate this possibility, I recommend another stomach X-ray in the morning before your daughter eats anything.

Delayed stomach clearance
Another possibility may be delayed stomach clearance. The medical term for this is gastroparesis. Research has shown that many individuals with Down syndrome have this condition. So it may be the case with your daughter.

That your daughter swallows food intact would not cause this condition. However, it may be adding to her stomach emptying problems.

The good news is that delayed stomach emptying can be treated with medication. It could be worth asking her physician for a trial of treatment of an appropriate medicine. Or consult a gastroenterologist who may have greater experience and comfort working through these possibilities.

Importantly, we know that poor stomach clearance can contribute to gastro-esophageal reflux. Reflux, likewise, has a number of possible treatments. You may want to talk with your daughter’s physician – or a gastroenterologist – about seeing if one of these treatments improves her breath. If it does, this would suggest she does, indeed, have reflux – a condition that should not be ignored for significant health reasons.

Also see Dr. Buie’s “Office Hours” video and Q&A on Acid Reflux and Autism here.

Any of these three possibilities – a bezoar, delayed stomach emptying and reflux – could be causing or contributing to your daughter’s foul breath. On rare occasion, other issues – such as liver dysfunction or constipation – cause bad breath. These, too, may be worth investigating.

I suggest discussing these possibilities with your daughter’s physician – perhaps with this blog post in hand to guide the conversation. If the doctor's not receptive, it’s reasonable to request a referral to a gastroenterologist to further discuss your daughter’s symptoms.

Thanks for reaching out with your question. Please let us know how you’re doing with a comment below or by emailing us again at

Editor’s note: The above information is not meant to diagnose or treat and should not take the place of consultation, as appropriate, with a qualified healthcare professional.

For more GI-autism advice and perspective from Dr. Buie, see his Autism Speaks “Office Hours” video and Q&A series here.

* Learn more about the Autism Speaks Autism Treatment Network here.
* Find the ATN center nearest you 
* Explore our archive of ATN expert-advice blogs and news stories 


The Autism Speaks blog features opinions from people throughout the autism community. Each blog represents the point of view of the author and does not necessarily reflect Autism Speaks' beliefs or point of view.