This is a diaper rash. And though it appears violent, it's nothing to worry about. Try to keep the baby dry. Avoid using a diaper. Use cotton cloth (langot) instead. You will have to keep changing it again and again, but it will help your baby in staying dry. Don't rub the rash. After the baby has passed stools or urine, clean the area with lukewarm water and allow it to air dry. Once the area is dry, apply a thick layer of siloderm ointment over the rash and let that dry as well. Another option is application of coconut oil over the affected area. This application of ointment or oil needs to be repeated after every stool. Give it a few days to heal. Don't panic.

It is a diaper rash only. Gentle wipes after each and every motion. Clean with cotton soaked with leukworm water Don't use wet wipes Don't use powder over rash area it may increase rash. Use siloderm mixi  ointment for perianal rash area It will help for early recovery.