Singer Jordin Sparks is recovering after emergency surgery to have her appendix removed.

The 19-year-old American Idol winner was slated to perform in Australia, with Australian Idol Guy Sebastian on Sunday, but was forced to scrap her appearance she was hospitalised with acute appendicitis on Wednesday night.

The singer logged on to her Twitter page from the recovery room on Thursday, posting a picture of herself and assuring fans she plans to be back on her feet in "the next week or so".

She added: "Feeling a little better but very sore. Thank you so much for your thoughts & prayers. It means so much & it's so powerful."