I'm kind of obsessing about colon cancer. so every now and then i catch myself putting pressure in my rectum analyzing if i feel anything abnormal.i feel like maybe stool is there but no urge to go though until hours later. is this tenesmus?

This is not tenesmus but is more likely heightened rectal sensitivity and/or a psychosomatic disorder with brain & GI system communication. I recommend consulting a mental health professional for evaluation and coaching.

Whn you are aware you are obsessing it is not too bad. You can get out of it. Your symptoms are functional. I suggest normal high fiber diet, moderate exercise, water. Keep yourself busy with activities of your choice, hiking, biking, walking painting volunteering etc. You may also try any form of meditation. You will be fine.