sympathy, pity, comfort
卹 centers on a compassionate response to suffering: feeling sympathy or pity, and offering comfort to someone in distress.
The exact historical development of 卹 is uncertain. It visually combines 血 (blood) and 卩 (a kneeling person), which may suggest a person bending over blood in a compassionate or pitying context, but this is speculative.
Picture a kneeling person (卩) beside a drop of blood (血), showing sympathy and offering comfort to someone who is hurt.
For シュツ, imagine comforting someone by saying 'shh, it's okay' while putting a bandage on: 'shh' + 'tsu' (the sound of a gentle touch) -> シュツ.