Colon cancer only causes pain when there's a blockage. There are so few symptoms that it is usually the last thing suspected or found by accident. I don't know what 'white stuff' in your stool would be unless you're having gall bladder problems and eat way too much fatty food. Are you intolerant to dairy? My back pain was gall bladder attacks.
White stools or pale gray stools can be a sign off liver problems but generally end stage liver failure. You'd know if that was going on. You said 'pain there' but didn't say 'where'. Rectal tumors or hemorrhoids can cause pressure and pain and diarrhea can be from nerves and cause the 'rhoids to sting, swell, ache. Nothing in your post says bowel cancer to me and since I've had Stage III and am now Stage IVa colon cancer, I've read it all....... for 5 years.