Isolate contracting of the BC muscle

I’m having trouble doing contractions of the bc muscle I always find my stomach and anus is clenching along with my bc muscle. Is there any technique to isolate clench the bc muscle only?

I might be wrong but if the bc muscle is the one thats flexed when u push outward (like trying to force a fart or shit) then i havent heard of a way to isolate. If thats what the BC muscle even is, i know what PC is but BC… i’m not 100% sure i’m correct on that1.

See this: Locating the bc muscle

It won’t hurt anything if other muscles are contracting while you attempt to do Kegel’s exercise.