Sorbitol is one several compounds called polyols, a group of low-digestible carbohydrates that provide a range of calories per gram—from 0.2 to 3. Many people know polyols as sugar alcohols. The preferred name is polyols because they are neither sugar nor alcohol.
 
Polyols are used in an array of food products, including chewing gum, candy, ice cream, baked goods, chocolate, and fruit spread. They are also used in toothpaste, mouthwash, and breath mints. Food manufacturers use polyols to replace sugars and/or fat to produce foods that are lower in calories, sugar, and/or fat. Polyols provide bulk to products such as low-fat, reduced sugar, and/or no-sugar-added baked goods, frozen dairy desserts, sauces, and salad dressings. Beyond sweetening, polyols are used for other functional benefits.

Polyols provide fewer calories per gram than other carbohydrates. This is because they are slowly and incompletely absorbed from the small intestine. Due to the incomplete absorption, a large amount of polyols consumed at one time may cause gastrointestinal effects, such as gas or laxative effects similar to reactions to beans and certain high-fiber foods. The severity of the symptoms depends on the individual, amount of the food that is consumed in one time, type of polyol, and existence of any prior period of adaptation.

The FDA is aware of the potential laxative effect of polyols. Therefore, they require the following informational food label statement on foods whose daily consumption may result in 50 grams of sorbitol or 20 grams of mannitol: “Excess consumption may have a laxative effect.”

Additional Resources:

http://www.eatright.org/Public/content.aspx?id=3662&terms=sorbitol
http://www.cspinet.org/new/schart.html
http://www.diabeteshealth.com/read/1999/12/01/1718/sorbitols-laxative-effect-might-cause-abdominal-problems/