<PAGE>   1
                      U.S. SECURITIES & EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

                                   FORM 10-QSB

(X)   Amended Quarterly report under section 13 or 15(d) of the Securities
Exchange Act of 1934 for the quarter period ended December 31, 1996.

( ) Transition report under Section 13 or 15(d) of the Securities Exchange Act
of 1934 for the transition period from       to        .

                          Commission File umber 0-9185

                            MEDCO HEALTH CORPORATION
                       (Formerly Williston Oil Corporation)

Nevada                                                                22-1934084
(State or other jurisdiction of             (IRS Employer Identification Number)
incorporated or organization)

532 Sylvan Avenue
Englewood Cliffs, New Jersey                                               07632
(address of Principal Executive Offices)                              (Zip Code)

                                  (201)541-8444
              (Registrant's telephone number, including area code)

                  Securities registered under Section 12(b) of
                               the Exchange Act:

                                      None

         Securities registered under Section 12(g) of the exchange Act:

                      Class A Common Stock, $.001 Par Value

         Check whether the issuer (1) filed all reports required to be filed by
Section 13 or 15(d) of the Exchange Act during the preceding twelve (12) months
(or for such shorter period that registrant was required to file such reports),
and (2) has been subject to such filing requirements for the past ninety (90)
days. YES (X) ( ).

                      Applicable Only to Corporate Issuers

         State the number of shares outstanding of each of the issuer's classes
of common equity:

           36, 695,543 Shares of Class A Common Stock, $.001 par value
           1,250,000 Shares of Class B. Common Stock, $.001 par value

                  Transitional Small Business Disclosure Format

                                YES ( ) NO (X)
<PAGE>   2
                            MEDCO HEALTH CORPORATION
                      (FORMERLY WILLISTON OIL CORPORATION)

                                TABLE OF CONTENTS

Part I

                                                                            Page

Item 1 - Financial Information

         Medco Health Corporation's Balance Sheets as of 12/31/96 and
         06/30/96                                                            1-2

         Statements of Operations for the three month period that
         ended 12/31/96, the six month period that ended on
         12/31/96, and the period from 07/01/94 to 12/31/96                  3-4

         Statements of Stockholders' Equity                                    5

         Statements of Cash Flows for the period that ended 12/31/96,
         and for the period ended 07/01/94 to 12/31/96                         6

         Notes to Financial Statements                                       7-9

Item 2 - Management's Discussion and Analysis of Financial Condition          10
         and Results of Operations

Part II

Item 1 - Legal Proceedings                                                    10

Item 2 - Changes in Securities                                             10-11

Item 3 - Defaults upon Senior Securities                                      11

Item 4 - Submission of Matter to a Vote of Security Holders                   11

Item 5 - Other Information                                                    11

Item 6 - Exhibits and Reports on Form S-B                                  11-12


                                  -i-
<PAGE>   3
Item 1. Financial Statements

        The financial statements of the company, are set forth below:

                Medco Health Corporation (formerly Medco, Inc.)
                         (A Development Stage Company)

                                 Balance Sheets

                                     Assets

<TABLE>
<CAPTION>
                                                December 31, 1996       June 30, 1996
                                                -----------------       -------------
<S>                                             <C>                     <C>
Current assets
 Cash                                               $   1,000               $  52,833
 Accounts receivable, net of allowance for
  doubtful accounts of $60,746                             --                      --
 Deposits on equipment                                     --                  32,000
 Prepaid expenses                                     117,000                  85,000
                                                    ---------               ---------

                                                      118,000                 169,833        
                                                    ---------               ---------
 Equipment, at cost, net of accumulated
  depreciation of $17,634-December, 1996 and
  $12,834-June, 1996

Other assets
 Organization costs, net of accumulated
  amortization of $1,500-December, 1996 and
  $1,000-June, 1996                                     3,500                   4,000

License fees                                            5,005                   5,005
                                                    ---------               ---------

                                                        8,505                   9,005
                                                    ---------               ---------
                                                 
                                                    $ 220,968               $ 204,930
                                                    =========               =========

                  Liability and Stockholder's Equity (Deficit)

Current liabilities
 Accrued expenses                                   $  19,453               $   3,050
 Income taxes payable                                     405                     405
                                                    ---------               ---------

                                                       19,858                   3,455
                                                    ---------               ---------


Due to stockholder                                    255,421                 231,406
                                                    ---------               ---------

Stockholder's equity (deficit)
 Common stock                                          38,128                  38,128
 Additional paid-in capital                            63,872                  63,872
 Deficit accumulated during the development stage    (156,311)               (131,931)
                                                    ---------               ---------

                                                      (54,311)                (29,931)
                                                    ---------               ---------

                                                    $ 220,968               $ 204,930
                                                    =========               =========
</TABLE>

                        See Notes to Financial Statements

                                      -1-
<PAGE>   4
                Medco Health Corporation (formerly Medco, Inc.)
                         (A Development Stage Company)

                            Statements of Operations

<TABLE>
<CAPTION>
                                                                              Cumulative
                         Three months                   Six months            Period from
                             ended                         ended             July 1, 1994
                          December 31,                  December 31,            (Date of
                        ----------------            --------------------      Inception) to
                        1995        1996            1995            1996    December 31, 1996
                        ----        ----            ----            ----    -----------------
<S>                   <C>       <C>               <C>           <C>         <C>
Revenues              $    --     $    --           $    --       $    --       $ 83,069

Cost of sales             179          --                --            --         16,939
                      -------     -------           -------       -------       --------

Gross profit             (179)         --                --            --         66,130
                      -------     -------           -------       -------       --------

General and 
 administrative 
 expenses:
 Payroll - officers        --          --                --        32,390         39,890
 Payroll - other           --          --                --         8,000         23,689
 Taxes and licenses       146       1,564               246         4,082          6,382
 Management fees           --       2,850                --         3,925          9,840
 Commission expense     6,737          --            13,871           200          8,600
 Travel                    --          --                --           450          7,324
 Miscellaneous             --         354               750         1,995          2,745
 Bad debt                  --          --                --            --         60,746
 Insurance                 --       5,389               605         8,169         13,457
 Supplies                  --         200               230         2,470          2,470
 Advertising              370          --               396            --          1,844
 Truck and auto 
  expenses                124         124               360           870          4,372
 Rent                   1,500       8,750             3,000        11,000         22,075
 Telephone                340         528             1,579           606          7,419
 Utilities                225         300               414           434          2,559
 Repairs and
  maintenance              --          --               138            35            987
 Office expense            98          25               497           219          1,887
 Seminars                  68          --                68            --            648
 Professional fees         --          --             1,000         4,045         11,718
 Depreciation and
  amortization          2,627       2,650             5,254         5,300         19,134
                      -------     -------           -------       -------       --------

                       12,235      22,734            28,408        84,380        247,786
                      -------     -------           -------       -------       --------

</TABLE>

                                      -2-
<PAGE>   5
                Medco Health Corporation (formerly Medco, Inc.)
                         (A Development Stage Company)
                                        
                            Statements of Operations

<TABLE>
<CAPTION>
<S>                          <C>        <C>       <C>       <C>       <C>

Operating loss                (12,414)   (22,734)  (26,510)  (84,180)  (181,656)

Gain (loss) on equipment           --         --        --    59,800     26,172
                             --------   --------  --------  --------  ---------
Loss before provision for
  income taxes                (12,414)   (22,734)  (26,510)  (24,380)  (155,484)

Provision for income taxes         --         --        --        --        827
                             --------   --------  --------  --------  ---------

Net loss                     $(12,414)  $(22,734) $(26,510) $(24,380) $(156,311)
                             ========   ========  ========  ========  =========

Net loss per common share    $     --   $     --  $     --  $     --  $      --
                             ========   ========  ========  ========  =========
</TABLE>

                       See Notes to Financial Statements

                                      -3-
<PAGE>   6
                Medco Health Corporation (formerly Medco, Inc.)
                         (A Development Stage Company)
                                        
                  Statements of Stockholders' Equity (Deficit)

<TABLE>
<CAPTION>

                                Common         Paid in        Retained
                                Stock          Capital        Earnings       Total
                               --------        ---------      --------      ---------
<S>                             <C>            <C>            <C>           <C>

Capital Contribution           $ 37,944        $ (27,944)     $      --     $  10,000
Net loss                             --              --         (42,665)      (42,665)
                               --------        ---------      ---------     --------- 
Balance, June 30, 1995           37,944          (27,944)     $ (42,665)      (32,665)
Net loss - June 30, 1996             --               --        (89,266)      (89,266)
Capital contributions               184           91,816             --        92,000
                               --------        ---------      ---------     ---------
Balance - June 30, 1996          38,128           63,872       (131,931)      (29,931)
Net Loss - December 31, 1996         --               --        (24,380)      (24,380)
                               --------        ---------      ---------     ---------
Balance - December 31, 1996    $ 38,128        $  63,872      $(156,311)    $ (54,311)
                               ========        =========      =========     =========
</TABLE>


                       See Notes to Financial Statements


                                      -4-
<PAGE>   7
                Medco Health Corporation (formerly Medco, Inc.)
                         (A Development Stage Company)

                            Statements of Cash Flows

<TABLE>
<CAPTION>
                                                                Cumulative
                                                                Period From
                                               Six Months       July 1, 1994
                                                 Ended           (Date of
                                              December 31,     Inception) to
                                                  1996       December 31, 1996
                                              ------------   -----------------
<S>                                            <C>              <C>
Operating activities
  Net loss                                     $(24,380)        $(156,311)
  Adjustments to reconcile net loss to net
  cash provided by operating activities:
     Depreciation and amortization                5,300            19,134
     Bad debts                                       --            60,746
  Change in assets and liabilities:
     (Increase) decrease in accounts
        receivable                                   --           (60,746)
     (Increase) in prepaid expenses             (32,000)         (117,000)
     Increase in accrued expenses                16,403            19,453
     (Decrease) Increase in income
        taxes payable                                --               405
                                               --------         ---------
Net cash used in operating activities           (34,677)         (234,319)
                                               --------         ---------
Investing activities:
  Organization costs                                 --            (5,000)
  License fees                                       --            (5,005)
  Deposits on equipment                          32,000                --
  Capital expenditures                          (73,171)         (112,097)
                                               --------         ---------
Net cash used in investing activities           (41,171)         (122,102)
                                               --------         ---------
Financing activities:
  Proceeds from stockholder loan                 25,965           455,234
  Repayment of stockholder loan                  (1,950)         (199,813)
  Proceeds from issuance of common stock             --            94,000
  Proceeds from additional paid-in-capital           --             8,000
                                               --------         ---------
Net cash provided by financing activities        24,015           357,421
                                               --------         ---------
Net (decrease) increase in cash                 (51,833)            1,000

Cash - beginning of period                       52,833                --
                                               --------         ---------
Cash - end of period                           $  1,000         $   1,000
                                               ========         =========

Supplemental Disclosure of Cash Flow Information:

  Interest paid                                $     --         $      --
                                               ========         =========
  Income taxes paid                            $     --         $     422
                                               ========         =========
</TABLE>

                       See Notes to Financial Statements


                                      -5-
<PAGE>   8
                MEDCO HEALTH CORPORATION (FORMERLY MEDCO, INC.)
                         (A DEVELOPMENT STAGE COMPANY)

                         Notes to Financial Statements

Note 1 - Summary of Accounting Policies
         ------------------------------

      Nature of Business
      ------------------
         Medco Health Corporation (formerly Medco, Inc.) (the "Company") was
         incorporated under the laws of the State of New York on July 1, 1994.
         The Company's principal business activities have been the marketing and
         distribution of medical equipment, supplies and health care services.

      Reorganization
      --------------
         On January 16, 1996 the sole shareholder of Medco, Inc. entered into an
         acquisition agreement (the "Acquisition Agreement") with Williston Oil
         Corporation for acquisition of all of the outstanding capital stock of
         Medco, Inc. in exchange for a portion of Williston's class A common
         stock and 100% of class B common stock. Subsequent to year end
         Williston Oil Corporation executed a name change to Medco Health
         Organization.

         In July 1983, an involuntary Chapter 11 bankruptcy petition was filed
         against Williston Oil Corporation by its creditors. In February 1992,
         the court granted the creditors' petition and an order for relief under
         Chapter 7 of the Bankruptcy Code was entered. Since 1992 the Company
         has remained inactive, and has no pre or post bankruptcy liabilities.

      Equipment
      ---------
         Equipment is recorded at cost less accumulated depreciation.
         Depreciation is provided over the estimated useful lives of the assets
         by using the straight-line method of depreciation.

         Repairs and maintenance costs are expensed as incurred while additions
         and betterments are capitalized. The cost and related accumulated
         depreciation of assets sold or retired are eliminated from the accounts
         and any gain or losses are reflected in earnings.

      Per Share Data
      --------------
         The primary income (loss) per share was computed on the weighted number
         of shares of common stock outstanding during the period. Common share
         equivalents were not included as their inclusion would have been
         anti-dilutive.

      Income Taxes
      ------------
         The Company has a net operating loss carryover of approximately
         $156,000 as of December 31, 1996, expiring in 2011.

         The Company adopted Statement of Financial Accounting Standards (SFAS)
         No. 109, Accounting for Income Taxes. SFAS No. 109 requires the
         establishment of a deferred tax asset for all deductible temporary
         differences and operating loss carryforwards. Because of the
         uncertainties discussed in Note 2, however, any deferred tax asset
         established for utilization of the Company's tax loss carryforwards
         would correspondingly require a valuation allowance of the same amount
         pursuant to SFAS No. 109. Accordingly, no deferred tax asset is
         reflected in these financial statements.

                                      -6-

<PAGE>   9
                Medco Health Corporation (formerly Medco, Inc.)
                -----------------------------------------------
                         (A Development Stage Company)
                         -----------------------------

                         Notes to Financial Statements


Note 2 -  Capital Stock
          -------------
          The following is a summary of the various classes of capital stock at
          September 30, 1996:

     Common Stock
     ------------
<TABLE>
          <S>                                         <C>
          Class A - Par value $.001 per share:
           authorized 100,000,000 shares;
           36,878,453 issued and outstanding           $ 36,878

          Class B - Par value $.001 per share:
           authorized 25,000,000 shares;
           1,250,000 issued and outstanding               1,250
                                                       --------
                                                       $ 38,128
                                                       ========
</TABLE>

     Preferred Stock
     ---------------
<TABLE>
          <S>                                          <C>
          Par value $.001 per share:
           authorized 25,000,000 shares;
           none issued and outstanding                 $      -
                                                       ========
</TABLE>

          The holders of Class A common stock possess the voting power of one
          vote for each share of stock held. The holders of Class A common stock
          do not possess any pre-emptive rights. Class A common stock holders
          have the right to elect a minority of the directors of the
          Corporation.

          The holders of Class B common stock possess the voting power of three
          votes for each share of stock held and do not possess any pre-emptive
          rights. Class B common stock holders have the right to elect the
          majority of the directors of the Corporation. Class B common stock
          holders will not be entitled to cash dividends only for a period of
          three (3) years from the original date of issuance of that share. The
          shares of Class B common stock shall be convertible at any time and
          from time to time at the option of the holder into one share of Class
          A common stock at the rate of one share of Class B common stock for
          one share of Class A common stock.

          Preferred stock may be issued, from time to time, in one or more
          series, each of such series to have such designations, preferences,
          and relative participating, optional or other special rights, and
          qualifications, limitations or restrictions thereof as are stated and
          expressed in the resolution or resolutions providing for the issue of
          such series, adopted by the Board of Directors.

Note 3 -  Going Concern
          -------------
          As shown in the accompanying financial statements, the Company
          incurred a net cumulative loss of $156,311 during the period July 1,
          1994 (date of inception) to December 31, 1996, and as of that date,
          the Company's total liabilities exceeded its total assets by $54,311.

                                      -7-
<PAGE>   10
                Medco Health Corporation (formerly Medco, Inc.)
                         (A Development Stage Company)
                                        
                         Notes to Financial Statements

Note 3 - Going Concern (continued)
         -------------------------
         In January 1996, the Company, under a plan of reorganization was merged
         into Williston Oil Corporation (Williston). Williston is a publicly
         traded  company. It is the intentions of management that the Company
         will obtain additional capital from a public offering. These factors
         create an uncertainty about the Company's ability to continue as a
         going concern. The financial statements do not include any adjustments
         that might be necessary if the Company is unable to continue as a going
         concern.

Note 4 - Related Party Transactions
         --------------------------
         During the period July 1, 1994 (date of inception) to December 31,
         1996, the stockholder advanced the Company approximately $255,000.
         There are no stated terms for repayment or interest on this advance.

Note 5 - Commitments and Contingencies
         -----------------------------
         The Company leases its facility under a operating lease which expires
         December 31, 1996. Lease expense for the period July 1, 1994 (date of
         inception) to September 30, 1995 amounted to $1,575 and $9,500 for the
         year ended September 30, 1996.

         Effective September 1996 the Company signed a lease for new facilities.
         The new lease will be for twenty years and will expire on August 30,
         2016 with minimum annual lease expense of $96,000.

         In addition the Company has entered into a contract for approximately
         $422,000 to have the new facilities constructed to accommodate their
         operations.

                                      -8-

<PAGE>   11
Item 2. Management's Discussion and Analysis of Financial Condition and Result
of Operations

         The following is management's discussion and analysis of significant
factors which have affected the Registrant's financial position and operations
during the fiscal quarter that ended December 31, 1996.

Liquidity and Capital Resources

         The activities of the registrant since its reorganization on January
16, 1996 have been financed by various loans and the sale of securities in
private transactions.

         The company currently owns three vehicles, a Land Cruiser, a BMW, and a
Dodge Colt. The company will also own the laboratory, including all of its
furnishings, once it is complete.

         The company currently has a negative net worth. There is no assurance
that the company will, in fact, be able to raise adequate funding and actually
expand its operations as contemplated, or even to bring its present operations
to a profitable level.

Results of Operations

         The company's revenues from its date of inception until December 31,
1996 is $83,069.00. However, the company had no revenue for the three months
that ended December 31, 1996.

         The management of the company has continued to devote the company's
resources to the completion of the clinical laboratory in Englewood Cliffs, New
Jersey.

Part II

Item 1.  Legal Proceedings

         The company is unaware of any pending legal proceedings to which the
Company is a party or of which any of its assets is the subject. No director,
officer or affiliate of the Company, or any associate of any of them, is a party
to or has a material interest in any proceeding adverse to the Company.

         There are no existing lawsuits against the Company.

Item 2.  Changes in Securities

         During the fiscal quarter that ended December 31, 1996, the Company
made no sales of its common stock, $.001 par value, per share.


                                       10
<PAGE>   12
Item 3. Defaults Upon Senior Securities

         For the period that ended on December 31, 1996, there was no defaults
upon senior securities or securities of any kind by the Company.

Item 4. Submission of Matters to a Vote of Security Holders

         For the period that ended on December 31, 1996, there were no matters
submitted to a vote of security holders of the Company.

Item 5. Other Information

         There is no other information that the Company believes is necessary to
be included in this report.

Item 6. Exhibits and Reports on Form S-K

         (a)      Exhibits filed herewith:

                  None

         (b)      Current reports on Form 10KSB; dated April 17, 1997, filed
with the Securities and Exchange Commission.


                                      -11-
<PAGE>   13
                                   SIGNATURES

         In accordance with the requirements of the Exchange Act, the registrant
caused this report to be signed on its behalf by the undersigned thereunto duly
authorized.

                                             MEDCO HEALTH CORPORATION



Date: November 26, 1997                      By:/s/ FAHIM SAHRAIE
                                                ----------------------------
                                                FAHIM SAHRAIE
                                                President/Director



Date: November 26, 1997                      By:/s/ HASHEM SAHRAIE
                                                ----------------------------
                                                HASHEM SAHRAIE
                                                Secretary/Director


                                      -12-