ALLENDORPH, MARK M MD is categorized under PHYSICIANS & SURGEONS specializing in GASTROENTEROLOGY and located at 111 E 4th St. Ste. 220 in or near the Alton, IL area. Find additional information including website, e-mail, map, and directions - OriginalYP.com®. Find additional PHYSICIANS & SURGEONS at MedicalYP.com ®.