The guitarist fell ill shortly before the group was due to perform in Florida on Friday (12Apr13), prompting Ian to skip the concert at the House of Blues.
A post on the band's official Twitter.com page read, "Sorry Orlando, it appears Scott came down with a case of the 'ol 'Double Fire Hydrant'".
Ian sought medical treatment the following day (13Apr13) and then pulled out of the band's gig at Tremont Music Hall in Charlotte, North Carolina on Saturday night, when he uploaded an image of his arm attached to an Intravenous drip.
But Ian's was back to form on Sunday (14Apr13) and travelled to Maryland with his bandmates for their show in Spring Hill, tweeting, "I'm back! After 2 days of my insides being caught in a mosh I'm back to normal. Thanks for all the kind words my friends."
And he was happy to return to the stage, adding, "Wow Maryland, tonight was amazing. You maniacs were insane. It felt great to be back on stage and your energy kept me going strong all night... Thanks again to all of you that wished me well on here (Twitter). I hated missing shows."