<prompt> What is the best method for confirming amyloidosis :-ColonoscopySigmoidoscopyRectal biopsyTongue biopsy  <response>: Answer is C Rectal biopsy: Rectal biopsy is single best answer amongst the options provided. The systemic amyloidosis offer a choice of biopsy sites. Abdominal fat aspirates or renal or rectal biopsies are often preferred. - Harrison 