Man with bleeding per rectum

A 65-year-old man present to the emergency department with complaint of bleeding per rectum. He did not complain of diarrhoea or abdominal pain. He had a history of chronic constipation. His past medical history was otherwise non-significant.

On examination, he had mild fever of 37.9 degree Celcius. He had no signs of anaemia. Abdominal examination showed mild tenderness at lower abdomen. Rectal examination show maroon-coloured blood. The examination was otherwise normal.

1. Name 2 possible diagnoses.

(Clue: bleeding with no complaint of abdominal pain/diarrhoea)

*Answers in comment*