Following text has been copied from the .flow wiki's page Back Ward.
The Back Ward (also, colloquially, the "Parade Ward") of the Alleyway Hospital is full of dead and dying children, with IVs, heart monitors, and bloodied, failing lamps lining the walls. You will also be able to find Little Sabitsuki here laying in her bed.
The children here don't react to the Handgun but will react to the Whistle and can be killed with the Pipe.
The leftmost entrance leads back to the Morgue, while the rightmost entrance, surrounded by heart monitors, leads to the Plant Labyrinth (past)
By going through the Back Ward, one will go into "Parade Ward" (パレード・病棟) through a passage with a large number of cardiac monitors and getting into an elevator.
The Parade Ward is a bloody white hallway with unstable lighting, plenty of IV drips, heart monitors, and dead children in this area, along with a Kaibutsu's laugh being heard. There are some living children, however, they look to be very ill and don't react to any Effects besides being killed with the Pipe, however, their bodies stay in place and they don't give money.
If one comes back during the same flow session, the children will be replaced with dead bodies but they'll respawn after the player wakes up and returns.
When visited by Rust, the Parade Ward has a couple of fetuses.
The only door that leads anywhere would be the one that leads to the Rust (錆), which appears to house a young Sabitski, lying in bed.
- Alleyway Hospital > head into the morgue and go to the very back of the area. You will come across a room full of lamps and hospital children. Go into the first room and take the elevator.
- There is a red mark at the very end of the corridor. If you smack it with the Iron pipe it will open and reveal itself as a red wound, possibly an orifice. And it will remove your currently equipped effect with a glitch screen effect if you interact with it a second time, You can only enter the orifice as Rust.
- There is an invincible girl at the end of the ward. She will not die if smacked with the pipe, however if a certain girl before the entrance is killed, then the invincible girl will die as well. This was fixed in later versions.
- If you go into the room down here there will be a little bloodied girl laying in the bed. It's been suspected that this could be Sabitsuki when she was younger as perhaps she had an illness that caused her to be bedridden for some time.