Abstract
From 1969 to the present, one thousand and sixx hunded colonoscopies were done. Irregular configurations of the colonoscope were investigated in 1400 examinations which the early 200 examinations in our series were eliminated because of our technical difficulties. They were seen mainly in the sigmoid or transverse colon ; frequency was calculated by dividing the number of irregular configurations by the total number that the colonoscope had passed through the above mentioned segments. In the sigmoid it was 8.2% (75/914), in the transverse colon 16.7% (115/690) and all together 11.8%. Irregular configurations of the sigmoid seemed to appear more frequently than those of the transverse colon, reason probably being that many efforts were made to remove the irregularity in the early portionn of the colonoscopic examination. In the sigmoid, double a-loops appeared most frequently; i.e. onethird of the times; it was followed by the reverse α-loop irregularity: i.e. 30.7 %. Remaining irregular configurations in the sigmoid were as follows; counter α-loop, double reverse α-loops, .A-loop, and complex knots. In the transverse colon, the γ-loop had the highest frequency; i. e. 65.2%. Such a high frequency of the γ-loop is apparently the result of less multiplicity in the irregular configuration of the colonoscope in the transverse colon. Sometimes artificial γ-loop formation is possible; in that instance the frequency will be 7.8% which is almost equivalent to that in the sigmoid, if the number of γ-loop deducted from them. Remaining irregular configurations in the transverse colon were as follows; left-flexure loop, reverse γ-loop, right flexure loop, and bilateral flexure loops. To remove them in the sigmoid was possible in almost all examinations, but it seemed to be further more difficult in the transverse colon, especially for the loops which were located over the right-sided colon. Even though disadvantages due to irregular configurations of the colonoscope have been described in a previous paper, the examiner has to decide in each case whether or not the irregularities would be able to be removed. Much additional information concerning the position of the colonoscope can be given by fluoroscopic assistance. So minimum use of fluoroscopy is recommended because of its effects on the human body and on the glassf fibers respectively.
