Hlthy 38yo guy-a lot blood on tp after straining to poop-dark poop-slight red water-anus painful. ab cat scan in aug ok. % of chance of colon cancer?

Colonoscopy: if you are having blood in your stool ultrasound does not show anything chance of cancer in your age is low but not zero you need to see a surgeon or GI specialists and most likely you need colonoscopy to determined what causing the problem most of the time it is a simple problem treated with regulating the bowel and medication

Hemorrhoids: Blood in stool probably bright red due to internal fissure or hemorrhoids. With previous exam and neg CAT scan one suspects rectal exam was neg and a very strong possibility no relationship to a tumor found. Proctoscopy should be performed and if neg. followed by colonoscopy to pinpoint nature of bleed.

See doctor: You will need a scpoe of your colon. Could be any number of causes including hemorroids, polyps and tumors.