The Sun reports the singer was admitted when she became ill in her St Lucia villa on Friday following another binge drinking session, but was discharged later that night.
Reports also say that Winehouse may postpone her planned concert at the Shepherd’s Bush Empire in London on May 31.
A source said: “Amy’s gig might as well be cancelled now. She’s not going to make it. It’s not worth her while even if she does make it, it will be a shambles.
“She is not ready for it and she proved it at the festival.”