Thank you for the query.
Such lump can be a hemorrhoid, rectal polyp, rectal cancer
or condyloma. Hemorrhoid is red or dark red in color, can be painful and usually gives fresh blood in the stool. Rectal polyp or rectal cancer can be painless however blood in stool
can be also present. Condyloma is painless lump caused by HPV infection
due to anal sex.
You should definitely visit your doctor for rectal examination
and possible colonoscopy. This should be diagnosed as cancer has to be ruled out.
Hope this will help.