Is it permissible to pray in underwear that has dry or old faecal impurity that cannot be removed by washing with soap and water, especially with the presence of obsessive-compulsive disorder that affects the performance of prayer? And how can impurity be seen in colored clothes? And how can one catch the congregational prayer when joining in the bowing of the first rak'ah? And is the fear of accidents and death considered a form of waswas (whispering/obsessive thoughts)?

Obsessive whispers are treated by completely disregarding them, paying them no attention, and asking Allah for well-being. It is not prescribed to search for impurities in clothes, as this is an excessive and rigid practice that opens the door to obsessive whispering. If an impurity is washed and its substance is removed, the clothes become pure, and the persistence of its color does not matter if its removal is difficult. The default is that clothes are pure unless their impurity is certain.