Th'Rynn's Spectacular Soiling

Choose one living creature that you can see. This creature's bowels are immediately enchanted, and it defecates on itself violently, and without warning. The creature must then make a Wisdom saving throw, or become Stunned. If the creature has an Intelligence score of 5 or lower, it is immune to this condition. The creature can re-roll their saving throw at the end of each of their turns. 

At higher levels. When you cast this spell using a spell slot of 2nd or higher, you can target one additional creature for each slot level above 1st.