We have about 60 female staff and four stalls. The way I see it, we all gotta poop, that's what bathrooms are for.
Therefore, if I gotta go (i get the old urgency too) I go.
Sometimes, I go into the stall and flush to cover the noise. Or I go in, they go about their business and I start to go about mine. Other times I go in to terminate the conversation but wait until they turn on the hand drier or something to eliminate the sound effects.
If someone comes in they will be in a stall before you come out so you don't have to face them so don't let them rush you.
Embarrassing story: I had a D-ish attack yesterday at work. I was washing my hands when a colleague came into the bathroom. She went into the stall that I had come out of and then came right back out and said that there was no TP in there. (I knew there was, she didn't know that I had come out of that one) Obviously there was a stench left behind by me