Warning: This article contains graphic medical images 

Just as your grandma always used to tell you, chewing your food is very important. But while you can ignore that old urban myth about how you should chew 32 times, this especially grisly clinical case shows why you should definitely take care to chomp your food (even if you have lost your dentures).

As reported in BMJ Case Reports, a man had a long stay in the hospital after his bowel became obstructed and then perforated by eating a “large amount of chestnuts” without chewing fully because he had lost his false teeth.

The 61-year-old man was rushed to a hospital in Victoria, Australia, after suffering from abdominal pain for over 12 hours, as well as nausea and vomiting. CT scans and a bunch of other medical tests were carried out. Doctors speculated whether the man had an underlying condition, such as a tumor or an internal hernia, however it quickly became clear that the numerous barely-chewed chesnuts in his bowel were the significant factor at play.

The extent of his condition was only realized after they began his keyhole surgery, scientifically known as a laparoscopy. The man’s unorthodox chestnut chewing had caused his small bowel to become pierced, or perforated, at least 10 times.

His bowels had also become obstructed due to phytobezoars. These are solidified masses in the gastrointestinal tract that consist of indigestible plant material such as fibers, skins, or seeds. Most people are not at a high risk of getting phytobezoars if they eat a normal diet, but they can be a problem if you’ve had recent gastric surgery or if you’re diabetic. Unfortunately for this man, his medical history showed he was also suffering from type 2 diabetes, heart disease, and hypertension.

To resolve the problem, the undigested chestnuts were then “milked out” through the hole in his bowel, in the words of the study authors. He then had to spend a further four weeks in the hospital due to the inability of his intestine to contract normally. For 12 of those days, he required nutrition administered elsewhere than the mouth.

“To the best of our knowledge, this is the first case reported whereby chestnut ingestion resulted in SBO [small bowel obstruction] with multiple perforations all throughout the length of the small bowel,” the study authors concluded.

However, they do note that there have been cases of single perforations caused by chestnut munching. There was also another case of a woman suffering from a bowel obstruction after swallowing a cherry tomato whole.