As filed with the Securities and Exchange Commission on February 23, 2007.
                                                     Registration No. 333-113894


                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                         POST-EFFECTIVE AMENDMENT NO. 1
                                   TO FORM S-3
                          REGISTRATION STATEMENT UNDER
                           THE SECURITIES ACT OF 1933


                              CONNETICS CORPORATION
             (Exact name of registrant as specified in its charter)

        Delaware                    3160 Porter Drive             94-3173928
(State or other jurisdiction   Palo Alto, California 94304    (I.R.S. Employer
     of incorporation or           (650) 843-2800         Identification Number)
       organization)

    (Address, including zip code, and telephone number, including area code,
                  of registrant's principal executive offices)


                               Jeffrey S. Thompson
                             Chief Executive Officer
                              CONNETICS CORPORATION
                                3160 Porter Drive
                           Palo Alto, California 94304
                                 (650) 843-2800

                                    Copies to
                               William Grant, Esq.
                          Willkie Farr & Gallagher LLP
                               787 Seventh Avenue
                               New York, NY 10019
                                 (212) 728-8000

            (Name, address, including zip code, and telephone number,
                   including area code, of agent for service)

Approximate date of commencement of proposed sale to public: Not applicable.


If the only securities being registered on this Form are being offered pursuant
to dividend or interest reinvestment plans, please check the following box. [ ]


If any of the securities being registered on this Form are to be offered on a
delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, other than securities offered only in connection with dividend or interest
reinvestment plans, check the following box. [ ]





If this Form is filed to register additional securities for an offering pursuant
to Rule 462(b) under the Securities Act, please check the following box and list
the Securities Act registration statement number of the earlier effective
registration statement for the same offering. [ ]


If this Form is a post-effective amendment filed pursuant to Rule 462(c) under
the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering. [ ]


If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box. [ ]




                          DEREGISTRATION OF SECURITIES


A Registration Statement on Form S-3 (Registration No. 333-113894) was
originally filed with the Securities and Exchange Commission (the "Commission")
on March 24, 2004 by the Registrant. The Registration Statement registered the
resale by certain selling securityholders named therein of up to 3,000,000
shares of the Registrant's common stock (the "Shares"). The Registrant is filing
this Post-Effective Amendment No. 1 to the Registration Statement to withdraw
from registration all unsold Shares previously registered for resale under the
Registration Statement.






                                   SIGNATURES

            Pursuant to the requirements of the Securities Act of 1933, the
undersigned Registrant certifies that it has reasonable grounds to believe that
it meets all of the requirements for filing on Form S-3 and has duly caused this
Post-Effective Amendment No. 1 to the Registration Statement to be signed on its
behalf by the undersigned, thereunto duly authorized, in the city of Palo Alto,
State of California, on February 23, 2007.

                                        CONNETICS CORPORATION



                                        By: /s/ Jeffrey S. Thompson
                                            ------------------------------------
                                            Name:  Jeffrey S. Thompson
                                            Title: Chief Executive Officer
                                                   (Principal Executive Officer)


     Pursuant to the requirements of the Securities Act of 1933, this
Post-Effective Amendment No. 1 to the Registration Statement has been signed on
February 23, 2007 by the following persons in the capacities indicated.

                                            /s/ Jeffrey S. Thompson
                                            ------------------------------------
                                            Name:  Jeffrey S. Thompson
                                            Title: Chief Executive Officer
                                                   (Principal Executive Officer)


                                            /s/ Michael Cornelius
                                            ------------------------------------
                                            Name:  Michael Cornelius
                                            Title: Executive Vice President
                                                   (Principal Financial Officer)


                                            /s/ Jeffrey Wadman
                                            ------------------------------------
                                            Name:  Jeffrey Wadman
                                            Title: Vice President
                                                  (Principal Accounting Officer)


                                           /s/ Charles W. Stiefel
                                           -------------------------------------
                                           Name:  Charles W. Stiefel
                                           Title: Director


                                           /s/ Brent Stiefel
                                           -------------------------------------
                                           Name:  Brent Stiefel
                                           Title: Director


                                           /s/ Michael Cornelius
                                           -------------------------------------
                                           Name:  Michael Cornelius
                                           Title: Director