Bad smell always coming from anus / anal part, i can't control it. it's embarrassing, some time secretion, feeling of warm air coming out?

Seek a doctor: Its hard to identify what the many causes of your symptoms can be without a thorough examination. I would seek a colorectal surgeon in your area as a place to start. It could represent an infection, a hemorrhoid issue, a hygiene issue, a fistula, etc. An experienced examiner will be able to guide you to identifying the problem and providing treatment.