A gastroenterologist removes polyps during a colonoscopy if they are present. at that same time, can he take a biopsy of a hardened area at the prostate? or, best to do at other time? the latter i would prefer. can i ask the md to wait?

No, a gastroenterologist cannot technically do a prostate biopsy during a colonoscopy. An urologist will be needed to weigh in and eventually proceed with an ultrasound assisted prostate biopsy if needed.

A gastroenterologist will not and cannot access the prostate gland for a biopsy during a colonoscopy. This is the province of a urologist who does it through the rectal wall or through the perineum which is between the anus & the scrotum.