Water nausea, as it turns out, is actually a lesser-understood phenomenon, so I spoke with Dr. Supriya Rao, MD — who is quadruple board-certified in internal medicine, gastroenterology, obesity medicine, and lifestyle medicine — to further explain these experiences.

As Dr. Rao puts it, there are several reasons why one could experience nausea after drinking water, and though it’s most common in bariatric patients (specifically those with gastric bypass), it could feasibly happen to anyone. One reason could be due to preexisting dehydration. “Patients may have some type of electrolyte imbalance because, with bypass patients, they’re not absorbing all the vitamins that they normally would,” she told BuzzFeed. 

Or, it could be the way that surgery is done, from a nervous system point of view. You’re changing things around in the gut, and it’s possible that the nerve endings are sending signals to make you feel nauseated, and that having something sweet would make it more palatable. Sugar, salt, and fat are more palatable ingredients in general.”

Source: https://www.buzzfeed.com/rossyoder/watertok-water-recipes-tiktok-trend-explainer