This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inflammatory Bowel Disease, Subject name: Medicine
FALSE statement about Ulcerative colitis is 
Select and explain. 
A. Smoking may prevent the disease, B. 58% concordance with monozygotic twins, C. 0% concordance with dizygotic twins, D. Appendectomy is protective for the disease
B: 58% concordance with monozygotic twins
Answer: B: 58% concordance with monozygotic twins 
Explanation: Patients with quiescent UC and CD have normal feility rates. The fallopian tubes can be scarred by the inflammatory process of CD, especially on the right side Ulcerative colitis Crohn's disease Male / female ratio 1:1 1.1 - 8.1 Smoking May prevent disease May cause disease Oral contraceptives No increased risk Odds ratio 1.4 Appendectomy Protective Not protective Monozygotic twins 6% concordance 58% concordance Dizygotic twins 0% concordance 4% concordance