[LazyPup]

Definitely change it out. While you might find an epoxy the would hold the pieces in place, it would not hold up to the internal stresses of hot and cold water. There would always be a serious risk of the bowl shattering from thermal stress, showering hundreds of extremely sharp edges on your feet.

Also, when changing it out, were good leather work gloves and be very careful when handling a cracked bowl or toilet. They can shatter without warning and the edges are like razor blades. r. rinard -journeyman plumber