"I have all of the confidence in the world in the clinical skills that I've developed over the last three years of Internal Medicine training. I know that I will be mastering new skills in clinical and procedural practice during Gastroenterology Fellowship training and I'm not worried on that end. The only things that would risk keeping me up at night coming into your program would be quickly learning an unfamiliar EMR and integrating quickly with the existing team of senior fellows. These are pressures that I put on myself to do in a timely manner and I would make them both a priority in my initial days with your program."

Put some thought to a question like this prior to your interview and use it as an opportunity to talk through any unknown questions that you want to be answered during your interview process. You can frame your answer to say that this question has been worrying you a bit and that you are hoping to get further clarification from your team of interviewers.