My father was diagnosed with polyps in his sigmoid colon it has 4 bits. We have conducted the biopsy twice and reports are benign. Colonoscopy and sigmoidoscopy was done too. As we proceed for the operation, one surgeon is saying his problem is still not diagnosed and talking about chemo and all the stuff. Another doctor is saying that colonoscopy NBI is required.so how should we proceed for further treatment?.. Kindly guide