Mumford and Sons bassist Ted Dwane has been discharged from hospital in America following treatment for a blood clot on his brain.
The bassist is now "on the road to a full recovery", according to the band's Facebook page.
The group, who were forced to postpone three shows on their American tour while Dwane underwent treatment, have decided to cancel all remaining gigs including an appearance at the Bonnaroo festival.
The statement reads: "It is with great joy that we can announce that Ted has been discharged from hospital and is on the road to a full recovery. The surgery went well, and the excellent medical team helping him are very pleased with his progress."
"He has been nothing short of heroic in how he has handled the whole ordeal, and now it has been medically proved that he does indeed have a brain."
It goes on: "Today, however, also marks the end of our Summer Stampede Tour. We were hoping to have made it out by Bonnaroo this weekend. But it is with sadness that we have to announce the cancellation of our scheduled performances at both Bonnaroo and Telluride Festivals, and our show at Cricket Wireless Amphitheatre in Bonner Springs, KS.
"If we could've we would've, you know that about us. We trust that you can respect our collective desire to encourage Ted to make a full recovery, and that this is based purely on the medical advice we have received."
The four-piece band, who shot to fame with their debut album, Sigh No More, in 2010, are due to headline at Glastonbury on 30 June.
No mention has been made about other upcoming festival appearances.
The Somerset festival's lineup has previously had to be reshuffled. Back in 2010 U2 had to cancel when singer Bono underwent surgery for a compressed sciatic nerve.
A Glastonbury source told The Mirror: "While Mumford & Sons still plan to perform at Glastonbury, organisers will surely be a little concerned about Ted's health and will be having a look at possible stand-ins should the worst come to the worst."