raw/ scabby bottom found on one of our chickens- advice?

[Marletts]

Just found this on one of our 4 chickens, they just started laying a couple weeks ago. She is in good spirits, eating fine, acting normal and appears to be laying. We were told to use diatomaceous earth to dust her and spread in coop for parasites, worms, etc. and topical cleaning spray and anti fungal/ bacterial treatment spray on the wound. Suggestions? And advice on what this is and the cause and treatment?

 

[Newmamabear]

Just found this on one of our 4 chickens, they just started laying a couple weeks ago. She is in good spirits, eating fine, acting normal and appears to be laying. We were told to use diatomaceous earth to dust her and spread in coop for parasites, worms, etc. and topical cleaning spray and anti fungal/ bacterial treatment spray on the wound. Suggestions? And advice on what this is and the cause and treatment?

This looks like vent gleet to me, some good threads with different treatment options on here