The doctor referred Harold to a physician that specialized in internal medicine and had Harold make an appointment for a procedure called anendoscopy.The endoscopy was performed at a hospital later that week. During the procedure, a long, thin tube was inserted into Harold's mouth and directed into hisdigestive tract. The end of the tube was equipped with a light source and a small camera which allowed the doctor to observe the interior of Harold's stomach. The endoscope was also equipped with a small claw-like structure that the doctor could use in order to obtain a small tissue sample from the lining of Harold's stomach, if required.