a three stall challenge

Oh the horror! Here's the setup: my office building is shared by a number of small businesses, so there is usually quite a bit of traffic up and down our halls. Our "facilities" are, of course, also shared, and there are two different bathroom options for everyone - gender-specific multi-person bathrooms at the end of the hall with three stalls each and two single person bathrooms accessible through the outside of the building. In my mind, the multi-person bathroom is appropriate for quick trips to the loo, as no one wants to hear or be overheard doing anything more involved than that. The outside bathrooms are where one goes to do one's actual dumping if need be. Right. Or so I thought. As I quickly popped into the bathroom at the end of the hall to drain my bladder this morning, I noticed that someone was in the middle of the three stalls. Weird enough, since people usually like to leave a little bit of space between themselves and others when taking a leak. However, as I darted into the third stall to take my much needed pee, I was hit with the stench of the person next to me taking a massive dump. Glancing at the floor, I could see her feet twisted in the effort of the act - was she trying to poo silently or did it really require that much effort? Egads. I couldn't pee fast enough. The smell...the horror... My question to you: what kind of person poops in the most central and public location in the building??