Is the imamate valid for someone who performs ablution for every prayer due to passing wind, or due to doubt about it, even though no foul odor is detected from him?

Scholars differ on the validity of a healthy person praying behind someone afflicted with urinary incontinence or continuous emission of gas, holding two views: The first view maintains that it is not permissible for such a person to lead the prayer unless those praying behind him are similarly afflicted, because his prayer has an imperfection. The second view holds that it is permissible for a healthy person to pray behind someone with incontinence. It is preferable, however, for someone with incontinence not to lead healthy people in prayer, to avoid the disagreement. It must be noted that mere doubt about the emission of gas does not nullify ablution; rather, certainty of its occurrence is required.