This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Large intestine, Subject name: Surgery
Which of the following is the least common possibility about Angiodysplasia of colon? 
Select and explain. 
A. Involvement of cecum, B. Involvement of rectum in 50% of cases, C. Affecting age group>40 years, D. Cause of troublesome lower GI haemorrhage
B: Involvement of rectum in 50% of cases
Answer: B: Involvement of rectum in 50% of cases 
Explanation: Vascular ectasia( Angiodysplasia) MC Vascular lesion found in the colon: Vascular ectasia MC cause of recurrent lower Intestinal bleeding after 60 years of age : Vascular ectasia Arise from age- related degeneration of previously normal colonic blood vessels. Acquired condition Almost always occur in the caecum or the proximal ascending colon Usually multiple, are < 5mm in diameter Rarely identified with gross inspection or routine pathologic examination Diagnosed with colonoscopy or angiography Angiography : Slow emptying of vein & dilation of sub mucosal vessels