Cigarette Smoking and Appendectomy are Risk Factors for Extraintestinal Manifestations in Ulcerative Colitis. - Manguso, F.; Sanges, M.; Staiano, T.; Gargiulo, S.; Nastro, P.; Gargano, D.; Somma, P.; Mansueto, G.; Peluso, R.; Scarpa, R.; D'Armiento, F. P.; Astarita, C.; et al. (American Journal of Gastroenterology (Springer Nature), 2004)