Does the presence of a small spot of impurity on the underwear every morning necessitate ghusl?

The spot a person sees after sleeping has several scenarios: 1. If it is confirmed to be mani (seminal fluid) due to a distinctive smell, then ghusl (ritual bath) is obligatory. 2. If it is certain to be madhiy (pre-seminal fluid), then purification of the area is obligatory, but ghusl is not. 3. If the nature of the spot is unknown, then one has the choice to consider it mani, in which case they perform ghusl, or madhiy, in which case they purify it. This is the view of the Shafi'i school.