Any over the counter FOBT kits are reliable... but, one symptom of colorectal cancer is INTERMITTENT bleeding; therefore not really that great if you have symptoms. So, if you have SEEN blood in your stool, go to a GI Specialist--- PLEASE. The sooner you do, you are doing yourself a favor.
I complained to my PC of bleeding when I was 28 and was told that it was probably a hemmorhoid, stress, or the Advil I was taking. She gave me a FOBT??? to do, which I did and sent back. She said if I didn't hear back from her to assume that everything was fine. Well, I did what I was told, never heard, and assumed all was well. Although I still experienced intermittent bleeding. Well at 31, when the bleeding got so bad, I was passing mucoid clots, and had increased frequency, I went to a GI Specialist. He scoped me and dx me with Stage 3C Rectal Cancer.
I recently found out that had I been scoped when I complained of bleeding, I probably would have been a Stage 1-- which is >90% curable vs. 20-40% now. How stupid of me to listen to my doctor!
Bottom line is-- why are you doing this? Do you have a family history? Are you bleeding? Do you have symptoms? Are you over 50 and want to start screening?? Please do yourself a favor and go see a GI Specialist with ANY symptoms and get a colonoscopy. It's really no big deal, compared to the alternative.
If you just want to take a proactive role, GOOD FOR YOU! But remember, part of that IS seeing a specialist.