HONG KONG — The reception area is welcoming, open and airy with tropical green trees and plants. The rooms have sofas, tables and chairs, well-chosen paintings, as well as the bed. Menus are prepared by international chefs who compete for the privilege of being chosen for a month at a time. But you won't find this hostelry on the hotel listings of Expedia, Orbitz or Asiarooms or any other Internet websites offering accommodations in exotic Asia.

That's because it is not a hotel but Bumrungrad International Hospital in Bangkok, which openly advertises for business on its sophisticated Internet site. It offers detailed information in English, Japanese and Thai, and boasts that its treatments cost 50 to 80 percent less than similar procedures in the United States, Europe or Japan.

Welcome to the multibillion dollar world of international medical tourism, a booming business in countries as far apart as Argentina, Costa Rica, Cuba, Hungary, India, Mexico, Singapore and Thailand, with the Philippines belatedly trying to climb aboard a business expected soon to be worth $100 billion.