The current British road race champion and 2015 world champion posted a photograph of herself on social media giving the thumbs up, pictured in a hospital bed after the procedure.
“I will be taking the rest of the season day by day after having my appendix removed last night… it’s not ideal but I’ll be alright,” the 28-year-old said.
Deignan had been taking part in the Boels Rental Ladies Tour of Holland this week, where she was 10th overall after stage two before appendicitis struck.
She took her first WorldTour victory of the season on Saturday, sprinting to win the GP Plouay in France ahead of Pauline Ferrand-Prevot.
Not only was Deignan likely to lead the GB squad at the 2017 UCI Road World Championships in Bergen, Norway (September 16-24) but she was also one of the front runners for victory in the women’s road race (September 23).