A 68 year old male is diagnosed of having colorectal cancer. What is the commonest presentation of Ca ascending colon ?

The presentation depends on the site of the cancer: Right colon cancers: weight loss, anemia, occult bleeding, mass in right iliac fossa, disease more likely to be advanced at presentation. Left colon cancers: often colicky pain, rectal bleeding, bowel obstruction, tenesmus, mass in left iliac fossa, early change in bowel habit, less advanced disease at presentation. A tumor in the left (descending) colon is likely to cause obstruction at an earlier stage, because the left colon has a smaller diameter and the stool is semisolid. Cancer tends to encircle this pa of the colon, causing alternating constipation and frequent bowel movements before obstruction. A tumor in the right (ascending) colon does not cause obstruction until late in the course of the cancer, because the ascending colon has a large diameter and the contents flowing through it are liquid.