Seronegative Status Is Associated with Less Severe Disease Phenotype in Newly Diagnosed Crohn's Disease in the Community: 637. (October 2016) - Mao, Eric J.; Shah, Samir A.; Mallette, Meaghan; Machan, Jason T.; Shapiro, Jason; Bright, Renee; Moniz, Heather; Merrick, Marjorie; Sands, Bruce