Exhibit 32.1

                    CERTIFICATION OF CHIEF EXECUTIVE OFFICER

         In connection with the periodic report of Connetics Corporation (the
"Company") on Form 10-K for the period ended December 31, 2003 as filed with the
Securities and Exchange Commission (the "Report"), I, Thomas G. Wiggans,
President and Chief Executive Officer of the Company, hereby certify as of the
date hereof, solely for purposes of Title 18, Chapter 63, Section 1350 of the
United States Code, that to the best of my knowledge:

         (1)      the Report fully complies with the requirements of
Section 13(a) or 15(d), as applicable, of the Securities Exchange Act of 1934,
and

         (2)      the information contained in the Report fairly presents, in
all material respects, the financial condition and results of operations of the
Company at the dates and for the periods indicated.

Date: March 11, 2004

      /s/ Thomas G. Wiggans
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Thomas G. Wiggans
President and Chief Executive Officer