Thanks for your response @jennifer0726. I will call his transplant team on Monday and hopefully they will respond quickly. Colonoscopy is scheduled for 5/5/23. Didn't think to ask the team because it was the Mayo nephrologist who reminded us a colonoscopy was overdue and he didn't make give any warnings about what colon prep to avoid! But of course it's better to be safe than not. Hope everything goes well with your surgery on 5/1/23!