"Running 102 fever since yesterday (Sunday). Severe loose motions. Sad that I won't be able to attend office today," Kejriwal tweeted Monday.
"It was so important to attend office today (Monday). We had planned the water announcement. God, bahut galat time par bimaar kiya (God, you made me fall ill at a wrong time)," he said.
Kejriwal's family doctor Vipin Mittal told reporters that he has diarrhoea and has been advised rest.
Senior party leader Kumar Vishwas said Kejriwal was very ill and doctors might have to put him on intravenous glucose if his health worsens.
However, the Delhi chief minister was in constant touch with the officials, Vishwas added.
Kejriwal, who was sworn in as Delhi chief minister Saturday, was unwell Sunday and could not attend a morning "havan" his father Govind Ram Kejriwal had organised.
He, however, met people at his Ghaziabad residence Sunday and heard their grievances.
He was supposed to attend his Delhi secretariat office Monday, as important announcements on Aam Aadmi Party's pre-poll promises are awaited.
--IANS (Posted on 30-12-2013)