NEW DELHI: Congress President Sonia Gandhi , who was on a visit to Shimla , was today rushed back to the national capital and admitted to the Sir Ganga Ram Hospital after she complained of stomach upset.D S Rana, Chairman (Board of Management) of the hospital said that Gandhi, 70, is under observation."Sonia Gandhi was brought to the hospital at 5pm today. She has been found to be suffering from stomach upset and has been admitted for observation," said Rana in a statement.According to sources, Gandhi was rushed to the hospital in an air-ambulance from Shimla, where she had gone for a vacation.A team of doctors from the hospital was deputed to bring her back from Shimla.Party sources said her condition was stable.