1. One should not begin Shemoneh Esreh if he feels the need to relieve himself and will have to go the bathroom within 72 minutes.
2. One must remove his Tefilin before he enters an area designated as a bathroom.
3. A person should not say Shemoneh Esreh while he is holding objects.
4. A person may not sleep while wearing Tefilin.
5. There is a dispute about whether one may use, for mundane purposes, a bag designated for holding Tefilin.
A BIT MORE
1. If he prays anyway, his prayer is an abomination.
2. He must do so from a distance of at least four cubits away from the bathroom.
3. He may not hold even Tefilin or a Sefer Torah, since one cannot have proper intent on his prayers when he is worried that the thing he is holding not fall.
4. This applies even if he plans on sleeping only for a very short time.
5. If it has already been set aside and used for the Tefilin, everyone agrees that it cannot be used for mundane purposes. If it has been set aside but not yet been used for Tefilin, Rav Nachman says that it may be used for mundane objects, while Abaye says that it may not.