| [ Summary ] |
The outer diameter of the distal end of a small caliber colonoscope of the PCF type (Olympus Optical Co., Ltd.) is small and its bendable section is short. Its insertion tube is soft and its caliber is also small. Therefore, in comparison with a large caliber colonoscope of the CF type, insertion of a PCF type colonoscope into the sigmoid colon is easier, especially in cases with advanced adhesions, in those with stenosis due to tumors, inflammation or diverticulosis, and also in those with inflammatory bowel disease. However, insertion beyond the sigmoid colon is sometimes difficult, due to loop formations of the scope. For that reason, small caliber colonoscopes with a variable stiffness function (the PCF-P240A and the PCF-Q260A) were developed. These colonoscopes can prevent loop formation after passage into the sigmoid colon by increasing the stiffness of the scope, making deeper insertion easier. |