Dr. Ann M Dilla has 4 locations. Mercy Clinic East 3524 E Milwaukee St Janesville, WI 53546. (608) 756-7100. ACCEPTING NEW PATIENTS. Centegra Physician Care 1906 Holian Dr Spring Grove, IL 60081. (815) 338-6600. ACCEPTING NEW PATIENTS. Centegra Health Center Northern Mchenry 2507 N Richmond Rd McHenry, IL 60051..