Reference: Sharh ‘Umdatil-Fiqh – Tape No.4, Question No.39
Question: I heard one of the scholars say that directly touching the bottom and the private parts does not invalidate the wudhoo, using as proof the hadeeth «it is just a part of you»?
Response: However, there is another hadeeth which is more authentic (stronger) than it, that the Prophet (sal-Allaahu ‘alayhi wa sallam) commanded the wudhoo [to be done again] for the one who has touched his private part; both of these [narrations] are in Buloogh al-Maraam. [So] you are taking one hadeeth and leaving the other?!
 «Whoever touched his private part, [then] let him do wudhoo»