To the Editor: Drs. Lees and Wilson, in their article, “The Treatment of Hyperlipidemia” (N Engl J Med 284:186-195, 1971) are to be complimented for their clear and concise explanation of hyperlipoproteinemia classification and terminology, and for their recommendation that these syndromes be treated preventively. We feel compelled to take them to task, however, for their irresponsible treatment of the partial ileal-bypass operation. In May, 1970, our clinical bypass program at the University of Minnesota entered the eighth year of study. At present, we have documented the preoperative, operative and postoperative course, with 100 per cent follow-up results, of over.