Henry Schoonyoung, MD Top Doctor 100 Lancaster Ave Suite 375 Wynnewood, Pennsylvania, 19096 Phone: 610-645-9093 Company Name: Marks Colorectal Surgical Associates Doctor Category: Oncology: Colorectal Profile Let this business know you found them on Main Line Today's Online Directories. Locations Wynnewood 100 Lancaster Ave Suite 375 Wynnewood, Pennsylvania 19096 Claim/Edit Listing