• If you are certain that the discharge came out while you were praying, or before you prayed [and after you did Wudu], then your prayer is invalid, and you have to clean yourself, purify your clothing and body of whatever got onto them, and do Wudu again and repeat the prayer. • If you are not sure whether the discharge came out while you were praying, or before or after that, then you do not have to repeat anything, because the basic principle is that you started praying in a state of purity, and the prayer cannot be deemed invalid on the basis of mere uncertainty.

The wisdom behind purification in Islam includes: 1. Purification is in harmony with the sound nature (fitrah) that Allah, may He be exalted, instilled in people. 2. Islam is a religion of cleanliness and beauty, and it encourages its followers to stand out among other people by cleaning their bodies, combing their hair, wearing the purest of clothes and smelling good. 3. Modern, well-founded scientific studies have proven that cleanliness and purification protect a person from many diseases, and that filth is the cause of many diseases. 4. The Muslim is required to meet and converse with his Lord, may He be exalted [in prayer]. 5. Whoever strives to purify his body and clothes from filth and impurities should be even keener to purify his heart and soul of bad characteristics.

If the cover of the Mus-haf is attached to it with binding or glue, it is not permissible for anyone to touch it without Wudu. If the cover is separate from the Mus-haf like the sleeve in which the Mus-haf is placed to protect it, there is nothing wrong with touching it without Wudu.

There is a concession allowing a woman to wear a wig if all of her hair has fallen out. If you wear a wig because of that, then you may wipe over it when doing wudu. However, you must take it off when doing ghusl, because it is obligatory to make the water reach all of the skin. For more, please see the detailed answer.