Hello and welcome to HCM, A white colored bump on anal opening is unlikely to be due to colon, rectal or anal cancer. Cancers of these organs are usually within the organ i.e. within colon, rectum and anal canal. Wart is a painless colorless lesion. A tender lesion could be due to skin boil or folliculitis. A boil is due to skin infection and folliculitis is due to infection and inflammation of the hair follicle. Both these lesions are painful, red in color and may be associated with pus collection. However, exact diagnosis can be made after clinical assessment. Kindly, consult your primary healthcare provider for clinical assessment. Thanks and take care Dr Shailja P Wahal