According to sources, Chidambaram, 74, is suffering from Crohn's disease, which causes inflammation in the digestive tract and can lead to abdominal pain, severe diarrhoea, fatigue, weight loss and malnutrition.
The former Minister could not get accustomed to foods served in Tihar Jail and complained of losing weight in the custody. After considering his health conditions and several requests, a Delhi court on October 3 allowed him home-cooked food once a day.
His deteriorating condition was visible during the court's proceedings too. On the very first day of remand hearing on August 22, Chidambaram had refused the judge's offer of a chair to sit during the proceedings. But later he was seen sitting during other proceedings.
According to sources, Crohn's disease was controlled after Chidambaram underwent medical treatment in a Hyderabad hospital. But it turned acute while he was in the judicial custody in the Tihar Jail.
He was taken to hospital first time on October 7. He was again taken to hospital on October 23 and October 25.
On Monday, Chidambaram was taken to All India Institute of Health Science (AIIMS), the fourth visit to a hospital. He was discharged after medication. Early in the day, he was taken to Ram Manohar Lohia Hospital. But was shifted to AIIMS.
Chidambaram is in the Enforcement Directorate (ED) custody till October 30 following arrest under the Prevention of Money-Laundering Act on October 16.
On October 24, Chidambaram has requested a Delhi court to grant him two-day interim bail for medication for acute stomach pain in a Hyderabad hospital. But the court directed that he be taken to AIIMS in a case of medical complication.
The Central Bureau of Investigation (CBI) arrested him on August 21 in the INX media corruption case. He was granted bail by the Supreme Court on October 22.
Chidambaram is being probed for his alleged involvement in irregularities in granting the Foreign Investment Promotion Board (FIPB) approval to INX Media during his term as the Finance Minister.