The party today issued a brief statement that 64-year-old Gandhi underwent a surgery on August 4 and the surgeon has indicated that the surgery has been successful.
At present, Gandhi is in ICU, a statement by Congress General Secretary Janardhan Dwivedi said. However, the statement did not disclose what was the surgery and the hospital and the country where it was performed.
Gandhi is reportedly in the US for the surgery. Children Rahul Gandhi and Priyanka Gandhi Vadra and son-in-law Robert Vadra are with Gandhi, the party said. Gandhi's family has requested that her privacy be respected.
"This is a personal matter that pertains to her health and medical treatment. Her family requests that her privacy be respected," Dwivedi said.
Gandhi had decided that in her absence a group comprising Rahul Gandhi and senior leaders A K Antony, Ahmed Patel and Dwivedi will look after party affairs.
Significance is attached to the fact that Rahul will form part of the of the committee that has only one senior minister of the government and two leaders from the organisation.
Asked to explain the absence of Prime Minister Manmohan Singh and Finance Minister Pranab Mukherjee from the group, Congress spokesperson Manish Tiwari had said yesterday "they (the Prime Minister and Finance Minister) are senior members who have been active in the organisation for long".
To a question about her health condition and the kind of surgery, she has to undergo, Tiwari had declined to go into details.
"Even public personalities are entitled to certain amount of privacy in so far as their medical condition is concerned. Our friends in media should bear that sensitivity in mind," he said.
The Congress President had been not keeping well in the past and because of her illness, she could not attend meetings of the Congress Core Group as also that of the Parliamentary Strategy Committee.