Fiqh-us-Sunnah Volume 3, Zakaat and Fasting, Fiqh 3.138.

Section : Actions that Void the Fast.

The actions that void the fast may be divided into two types:

1. those which void the fast and require that the day be made up later, and

2. those which void the fast and, in addition to being made up, also require an act of expiation.