Ill. Const. art. IV, § 7 – Transaction of Business

(a) Committees of each house, joint committees of the two houses and legislative commissions shall give reasonable public notice of meetings, including a statement of subjects to be considered.
(b) Each house shall keep a journal of its proceedings and a transcript of its debates. The journal shall be published and the transcript shall be available to the public.
(c) Either house or any committee thereof as provided by law may compel by subpoena the attendance and testimony of witnesses and the production of books, records and papers.