All of the following are samples of rigid endoscopes except:

The colonoscope is not categorized as a rigid endoscope; it is a flexible endoscope designed for examining the entire colon. This instrument features a flexible shaft that allows for greater maneuverability through the twists and turns of the colon, making it suitable for procedures like colonoscopies.

In contrast, laparoscopes, cystoscopes, and arthroscopes are considered rigid endoscopes as they possess a solid construction with limited flexibility. Laparoscopes are utilized for minimally invasive surgical procedures within the abdominal or pelvic cavity. Cystoscopes are employed to visualize the interior of the bladder, while arthroscopes are used to investigate joint cavities. Each of these tools features a rigid lens system designed for specific diagnostic or therapeutic applications. Thus, the correct classification of these instruments highlights the critical differences between rigid and flexible endoscopic devices in medical procedures.