Chia seeds have become increasingly popular in the last few years. Small and oval, originally sold as the novelty gift, Chia Pets, chia seeds are high in fiber, protein, and omega-3 fatty acids, and low in calories.

They also can pose a choking hazard.

Chia seeds enlarge when placed in water, absorbing up to 27 times their weight. In the stomach, this makes you feel full. But the problem is they don't always make it to the stomach. Swallowing dry seeds with fluid can result in a gel forming in or near the esophagus that becomes stuck and is extremely difficult to remove.

A blockage occurred recently in a 39-year-old man who had eaten a tablespoon of dry chia seeds and then drank a glass of water.

People who eat chia seeds should be sure to mix them with water and let them expand before eating them. This is especially true for anyone with a history of trouble swallowing or problems with their throat or esophagus.

Such a blockage occurred recently in a 39-year-old man who had eaten a tablespoon of dry chia seeds and then drank a glass of water. He had had a history of swallowing problems, asthma and seasonal allergies. The seeds formed a hard gel — more like Play-Doh in consistency than Jell-O — that became lodged in his esophagus. The blockage was so severe that the man was choking on his own saliva.

Doctors treating him in a nearby emergency room had great difficulty removing the blockage. Traditional tools, such as an adult endoscope and a forceps, were ineffective. Eventually, a tiny endoscope made for babies was able to push small pieces of the gel into the stomach until what was left became small enough to dislodge all at once. Doctors described the procedure as labor intensive.

The doctor who removed the blockage, Rebecca Rawl, MD, MPH, said that this was the first case of blockage by chia seeds that she's heard of, but she expects with their increasing popularity there will be more cases. She notes that when used properly and first mixed with water, chia seeds are safe. People with a history of trouble swallowing or esophageal narrowing, however, should be cautioned about their use, especially in their dry form, she said.

The case was presented at The American College of Gastroenterology's 2014 Annual Meeting in Philadelphia on October 20.