Yonder Mountain String Band’s Ben Kaufmann will miss the first few shows of the band’s upcoming spring tour after being hospitalized with an unexpected illness.

In a message posted on the Yonder Mountain Facebook page, Kaufmann says that he has a dissection of his renal artery, which restricts blood flow to the kidney. He will undergo surgery tomorrow to help repair the dissection and increase blood flow to the kidneys.

In the interim, Alan Bartram from The Travelin’ McCourys will join the band until Kaufmann is fit to return to the road. Read the full message below.

Dear Kinfolk,
We regret to inform you that due to an unexpected illness, Ben Kaufmann will miss the first few shows of this week’s Spring Tour. We’re hoping for a speedy recovery and that he’ll join us back on the road later this week. Until then, our good friend Alan Bartram from The Travelin’ McCourys will join us beginning today in Manhattan, KS. We’ll keep you posted on Ben’s return, and we look forward to seeing you this week. Until then, here’s a personal message from Ben.