Answer:
"apple pectin, -carrageenan, locust bean gum, gum xanthan, guar gum or sodium (Na) alginate"
Be careful, though. This comes from a study that discovered that rats, when fed these indigestible polysaccharides, develop hyperplasia of the digestive organs to compensate for the inefficiency of the meal.
http://jn.nutrition.org/cgi/content/abstract/120/4/353
This can lead to polyps and potentially precancerous cells, so I'd advice you to reconsider and just eat foods high in water insoluble fiber instead. Water insoluble fibers trap water and aid in elimination, unlike water soluble fibers (apple pectin, gum, etc), and can be found in wheats and whole bran.
http://www.ext.colostate.edu/PUBS/FOODNUT/09333.html
Good luck!