This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
The impoant symptom of radiation proctitis is: 
Select and explain. 
A. Bleeding PR, B. Weight loss, C. Loss of weight, D. Colicky abdominal pain
A: Bleeding PR
Answer: A: Bleeding PR 
Explanation: Radiation proctitis can lead to persistent rectal bleeding and iron deficiency anemia. Other symptoms include diarrhea, mucoid discharge, urgency, tenesmus, rectal pain and fecal incontinence. Ref: World J Gastroenterol 2011 November 7; 17(41): 4554-4562.