The gastroenterology specialty could benefit from the introduction of Computer Assisted Decision (CAD) systems, since gastric cancer is a serious concern in which an accurate and early diagnosis usually leads to a good prognosis. Still, the way doctors interact with these systems is very important because it will often determine its embracement or rejection, as any gains in productivity will frequently hinge on how comfortable they are with it. Using other types of interaction paradigms such as voice and motion control, is important in a way that typical inputs such as keyboard and mouse are sometimes not the best choice for certain clinical scenarios. In order to ascertain how a doctor could control a hypothetical CAD system during a gastroenterology exam, we measured the natural response of users when faced with three different task requests, using three types of interaction paradigms: voice, gesture and endoscope. Results fit in what was expected, with gesture control being the most intuitive to use, and the endoscope being on the other edge. All the technologies are mature enough to cope with the response concepts the participants gave us. However, when having into account the scenario context, better natural response scores may not always be the best choice for implementation. That way, simplification or reduction of tasks, along with a well tought-out interface, or even mixing more oriented paradigms for particular requests, could allow for better system control with fewer inconveniences for the user.