Hello welcome
Bedsores at the sacral area
Inthe image you have uploaded, there is devitalized( dead ) tissue present.
It is the source of microorganisms, to spread and damage
That tissue should be removed immediately
With antibiotics cream topically
If needed collagen powder may be applied
If he is diabetic, good
sugar control is important
Next Steps
kindly consult a surgeon at your locality, and the dead tissue to be removed
Health Tips
frequent mobilisation of your father from bed atleast side to side
water bed or
Alpha bed
good nutrition
Anemia correction