In one recent case study, a 39 year old man was taken to hospital with complaints of dysphagia, or difficulty swallowing. He has ingested a tablespoon of dried chia seeds and chased it with water — causing the seeds the expand in his esophagus, where they got stuck.
Unfortunately, traditional medical tools were unable to remove the gelatinous chia cluster, so doctors were forced to improvise a new method (using a gastroscope for premature infants) to push it down into his stomach.