Eight-month-old Cheng Aobing, who suffers from kidney stones, receives medical treatment at a hospital in Hefei, Anhui province September 14, 2008. China’s investigation of the tainted milk powder that sickened hundreds of babies widened to its dairy-producing regions on Sunday, as officials attempted to track down the source of melamine in the milk. REUTERS/Stringer (CHINA). CHINA OUT. NO COMMERCIAL OR EDITORIAL SALES IN CHINA.