mucus precedes feces - feces are smaller than usual

Hello Anon

Thank you for writing.

Humans have some mucus in their stool - it is there to lubricate the digestive system/colon. It's normal for excess to leave the body in a bowel movement. Small feces don't necessarily indicate anything serious although for some, it can mean constipation. A lot of water and extra fiber can help with this.
If you have further questions, consult your doctor.
Best,
Susan