Gastroenterology 3331 West DeYoung Street Suite 109 Marion, IL 62959 Gastroenterology Hours: Monday - Friday: 8:00 am - 4:30 pm Phone: 618-998-7155 Call 618-998-7239 to make an appointment. ASSOCIATED CARE Gastroenterology Colorectal Cancer ASSOCIATED PROVIDERS Yazan Abu Qwaider, MD