Trump shit his pants during his speech in Detroit. The evidence of it can be heard on the video tape:

https://www.youtube.com/watch?v=NxGkCiUeA-w

It was wet diarrhea that leaked past the protective diaper he was wearing, trickled down his leg and left a sizable puddle of shit on the stage floor.

His team attempted to prevent future blowouts in his diapers by reinforcing his diapers with an elastic leg cuff layer. The elastic in the leg cuffs caused his suit pants to bunch and wrinkle in a very noticeable way.

This is why Trump cancelled so many interviews in the week following his Detroit speech. If he reduces his Adderall and stimulant consumption so he doesn't have liquid shits anytime he stands then he's so exhausted looking his mind wanders noticeably. If he maintains his current level of uppers he risks shitting himself so badly it leaks.