POWER OF ATTORNEY

The undersigned constitutes and appoints BRIAN J. SMITH, TERRENCE
C. KEARNEY and HENRY WEISHAAR, and each of them individually, as
the undersigned's true and lawful attorney-in-fact and agent,
with full power of substitution and resubstitution, for the
undersigned and in the undersigned's name, place and
stead, to sign any and all Securities and Exchange Commission
("SEC") statements of beneficial ownership of securities on Forms
3, 4 and 5 as required under Section 16(a) of the Securities
Exchange Act of 1934, and to file the same with all exhibits
thereto, and other documents in connection therewith, with the
SEC, granting unto said attorney-in-fact and agent full power and
authority to do and perform each act and thing requisite and
necessary to be done under said Section 16(a), as fully for all
intents and purposes as the undersigned might or could do in
person, hereby ratifying and confirming all that said attorney-
in-fact and agent may lawfully do or cause to be done by virtue
hereof.

A copy of this power of attorney shall be filed with the SEC.
The authorization set forth above shall continue in full force
and effect until the undersigned revokes such authorization by
written instructions to the attorney-in-fact.

Dated May 3, 2004

/s/ Irving W. Bailey II
Signature of Reporting Person
Irving W. Bailey II
Director