If a 2d creature has two orifices, then it's bisected. The two parts of it's body can't be connected without interrupting the digestive tract. It's like saying

If a 2d creature has two orifices, then it's bisected. The two parts of it's body can't be connected without interrupting the digestive tract. It's like saying of us 3d creatures: "the butt doesn't have to be connected to the head, does it?"