405 ILCS 5/3-603

(a) If no physician, qualified examiner, psychiatrist, advanced practice psychiatric nurse, or clinical psychologist is immediately available or it is not possible after a diligent effort to obtain the certificate provided for in Section 3-602, the respondent may be detained for examination in a mental health facility upon presentation of the petition alone pending the obtaining of such a certificate.

(b) In such instance the petition shall conform to the requirements of Section 3-601 and further specify that:

1. the petitioner believes, as a result of his personal observation, that the respondent is subject to involuntary admission on an inpatient basis;

2. a diligent effort was made to obtain a certificate;

3. no physician, qualified examiner, psychiatrist, or clinical psychologist could be found who has examined or could examine the respondent; and

4. a diligent effort has been made to convince the respondent to appear voluntarily for examination by a physician, qualified examiner, psychiatrist, or clinical psychologist, unless the petitioner reasonably believes that effort would impose a risk of harm to the respondent or others.