I have a knot like lump on the inside of my rectum. cancer does run in my family. should i be worried?

Ease your mind: You should not keep wondering about this especially with a significant family history of cancer. .To ease your mind, go to see your doctor. She/he can check it and if that feels suspicious or if your case looks suspicious- further evaluation then will need to be done- including perhaps a visit to a gastroenterologist for further GI work-up including a colonsocopy if you never have this done.

Consult your doctor: Lump in the rectum should be checked out asap, and biopsied if there is a mass so that the lesion may be examined by a pathologist for definitive diagnosis.

Rectal lesions: There can be a somewhat higher risk of colon and rectum cancers in those with a family history, and evaluation by endoscopy can be helpful for diagnosis and for screening, among other screening options, such as radiological tests and evaluating for blood in stool. Endoscopy allows one to biopsy a lesion if one is visualized to make a determination if there is cancer.