<prompt> COMMONEST presentation of Carcinoma rectum is:DiarrheaConstipationBleeding per rectumFeeling of incomplete defecation  <response>: Bleeding is the earliest and most common symptom. Often the bleeding is slight in amount. Alteration in the bowel habit is the next most frequent symptom. An early morning urgency may occur bit he passes only mucous and blood early morning bloody diarrhea. An annular carcinoma at pelvi-rectal junction may lead to constipation and obstruction. Other symptoms are: Tenesmus: almost invariably present in tumor of lower half of rectum. Pain: is a late symptom. Weight loss Ref: Bailey Love 25e, Page 1231. 