Urge to Break Wind in Salaah

Q: I was performing salaah and during my last sajdah I felt accumulated wind about to come out i.e. I had the urge to break wind, when I sat back from sajdah that feeling was gone. Now I don't know whether the accumulated wind came out without me noticing it, or that the accumulated wind just disappeared into my body. In such case is my wudhu nullified? Can the feeling of accumulated wind just disappear (without coming out) back into the body? Or must I regard it as having come out even if I did not feel something coming out? Should I repeat the prayer and the prayer I have prayed after it?

Mazi Falling on the Garment

Q: Before going to sleep, very small amount of mazi comes out. After waking up it is impossible to locate exactly which part of the garment has the impurity. What should be done in this case? Can salaah be offered without washing the garment since the mazi is not apparent?