According to a flight attendant (FA) on Southwest Airlines flight 2046, during cruise flight with no reported turbulence, she and several passengers noticed the forward lavatory was occupied for an unusually long time (10-15 minutes) requiring passengers to use the back lavatory. The FA realized the passenger had unlocked the lavatory door and cracked it open but did not exit. She knocked on the door and asked if everything was okay but there was no response. When the FA attempted to open the door, a female passenger started to exit the lavatory when she began to fall and grabbed on to the FA. The FA immediately requested for the front two passengers to assist her in getting the passenger up and moved to a seat. While assisting the passenger, the FA noticed the passenger’s foot was swollen and piece of bone was sticking through her skin. A volunteer medical professional who was onboard the airplane assisted and positioned the injured passenger in the front galley for landing. Emergency medical personnel met the airplane at the gate and transported the passenger to a local hospital.