Clinicians are trained to manipulate a colonoscope while minimizing the force exerted on the colon walls to reduce the danger of luminal perforation and discomfort to the patient. Here, we classify the expertise of the clinician performing colonoscopy using a Hidden Markov Model. Seven models are trained corresponding to the performance of the expert in the entire colon, ascending, transverse and descending colon and three gestures corresponding to roll and two angulations of the distal end of the scope. Experimental results in a colon model (CM-1, Olympus, Tokyo, Japan) are shown to compare the performance of the four groups of users - first year, second year and third year GI residents and expert physicians.