When the bowel is well prepared it eases the insertion of the scope and significantly improves the effectiveness of the examination. The camera can’t see through fecal debris. Any fecal debris left in the colon could block the doctor’s ability to navigate the scope forward and block identification of a polyp or even a small cancer.
If the doctor does not have good confidence in the exam due to a poor prep, you will likely have to repeat the exam again earlier than normally recommended. Individuals usually underestimate how clean their bowels are. All doses of the bowel prep are important but the morning-of-procedure dose is especially important in cleaning the right colon where growths can be more difficult to see. Even though it is difficult, please make sure you complete the entire prep.