Brief Answer:
Do not worry about anal/colon cancer

Detailed Answer:
Hello, XXXX
1) Do you have occasional constipation?
2) Reason to ask this is because, if you had to do straining for defecation or if you pass hard stool then these conditions cause a) feeling of small blood vessels under the wall of anal canal and develop hemorrhoid from that and b) excessive straining cause anal fissure to develop
3) Anal fissure develop when there is minor linear friction type injury to inner most layer of anal canal wall (mucosa)
4) Pain around anus, occasional episode of small amount of fresh blood on surface of stool/on wiping anus are suggestive of suggestive of anal fissure. Yes, anal intercourse is an aggravating factor for this and you should avoid it for period of time
4) During acute phase of anal fissure lower-most part would be swollen and reddened which cause excessive pain during either passing stool or doing anal intercourse with occasional episodes of bleeding. In contrast, Fissure since long duration doesn't have that much pain as damaged part of wall of anal canal is getting healed slowly.
5) This can be confirmed by simple digital rectal examination and proctoscopy.
6) Anal fissure can not be cured with medical treatment. Medical treatment is only to relieve from symptoms. Repeated episodes of symptoms from fissure require surgery
7) Now to clear your doubt about cancer; Generally, colon/anal cancer develop in older age group (>45year of age), initial symptoms would be mild non-specific abdominal pain, blood loss in stool since long time (which cause low hemoglobin on CBC report), loss of weight, decreased appetite.
8) Blood test of CEA is considered as a screening test for colon cancer, i.e. if CEA level comes high in your blood report with continue episodes of bleeding episode then proceed for colonoscopy.
9) As such, anal fissure does not cause development of colon/anal canal cancer.

Hope I have answered your concerned query. If you have any further question, i would be happy to help you.

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