If you consume too much sorbitol, which is found in some sugar-free products, it can cause pain and diarrhea. According to a 2008 article in BMJ , a 21-year-old woman had an 11-pound weight loss, abdominal pain, and diarrhea (as many as 12 bowel movements a day) from chewing about 16 sticks of gum a day.
A 46-year-old man had similar symptoms after chewing about 20 sticks of sugarless gum and eating sorbitol-containing sweets daily. "Sorbitol goes into your GI tract and since your body can't absorb it, it gets to the bacteria in your colon, which eat it and produce gas and fluids that contribute to diarrhea," explains Dr. Raymond.
To fix the problem, cut back on the amount of sugarless gum you chew.