Slipknot were forced to pull-out of a US festival this past Saturday (August 22) due to drummer Joey Jordison being hospitalised.The band were set to headline Seattle radio station KISW 99.9 FM's Pain In The Grass festival in Auburn, Washington alongside Steel Panther, Static-X, Saliva and Mudvayne when Jordison was taken to hospital for undisclosed health reasons.According to a spokesperson for the band, the drummer hoped to make a full recovery and rejoin the band for last night's show in Kennewick, Washington. However doctors advised Jordison to rest.Slipknot hope to reschedule the dates later this year.Slipknot cancelled a number of European festival shows this time last year (including the UK's Reading and Leeds festivals) after Jordison reportedly "broke his ankle from drumming too hard."