<prompt> Commonest presentation of Ca rectum is:DiarrhoeaConstipationBleeding PRFeeling of incomplete defaecation  <response>: Bleeding is the earliest and most common symptom. Often the bleeding is slight in amount.Alteration in bowel habit is the next most frequent symptom. An early morning urgency may occur but he passes only mucus blood early morning bloody diarrhea. An annular carcinoma at pelvi-rectal jn. may lead to constipation obstruction.Other symptoms are -Tenesmus - almost invariably present in tumors of lower half of rectum.Pain - is a late symptom.Weight loss. 