Background/Aims: Colorectal polyp detection during colonoscopy is influenced by the lesion location, size, morphology, and histology. However, no studies have systematically assessed the difficulty of detection along the short axis of the intestinal lumen. This study aimed to evaluate the colorectal polyp detection rates on this axis during colonoscopy. Methods: This retrospective study analyzed 1,169 polyps in 513 patients who underwent colonoscopy at Showa University Hospital between November 2022 and February 2023. The short-axis lumen was divided into: upper right, lower right, lower left, and upper left. Each polyp detected was assigned to a quadrant. Detection rates were compared across quadrants and analyzed for associations with clinicopathological factors including lesion size, location, macroscopic type, and examiner experience. Results: The lesion detection rates varied significantly by quadrant. The upper left quadrant had the lowest detection rate (17.5%) compared with the expected 25.0% per quadrant. Subgroup analyses consistently confirmed the lower detection rates in this quadrant across most lesion types and patient groups, except for lesions in the cecum and rectum. Conclusions The lower detection rate in the upper left quadrant suggests that this orientation poses a challenge and may increase the number of missed lesions. Enhanced examination of this area may improve detection; however, further prospective studies are required.

Objective: In The Hospital of Hyogo College of Medicine, a oral rinse containing polaprezinc (PZ), a zinc-containing drug for gastric ulcers, was used as a hospital preparation to treat radiotherapy-related oral mucositis, and its efficacy was reported.  However, the dispersibility of PZ for carboxymethylcellulose sodium (CMC), which was used as the base of the oral rinse, was unfavorable, raising an issue.  In this study, we newly prepared a PZ oral rinse containing carboxyvinyl polymer (CP) as a base, and examined its usefulness.
Methods: A questionnaire survey regarding the usefulness involving 10 healthy volunteers and a pharmaceutical test were conducted.
Results: The results of the questionnaire survey showed that the optimal concentration of CP was 0.5%.  There were no serial changes in the pH, adhesiveness, or PZ content for 7 days after preparation.  Furthermore, there were no differences between CMC and CP.  The dispersibility of PZ in the oral rinse containing CP as a base was more favorable than that in the oral rinse containing CMC.
Conclusion: The results of this study suggest that the PZ oral rinse containing 0.5% CP as a base is useful, and that its stability is similar to that of the oral rinse containing CMC as a base.

Objective: Oral mucositis is one of the serious and frequent acute side effects due to chemoradiotherapy (CRT) for head and neck cancer.  In this study, we prepared an oral rinse as a hospital preparation for the treatment of oral mucositis, which was a suspension of polaprezinc (PZ), a zinc-containing therapeutic agent for gastric ulcer, in carboxyvinyl polymer (CP), a water-soluble large molecule.
Methods: We carried out stability tests of the PZ-CP oral rinse, and investigated its effects on the radiation-induced oral mucositis in patients who received CRT for head and neck cancer.
Results: In the stability test, the pH, viscosity, adhesion and PZ content in the preparations did not change throughout 28 days after preparation.  In the clinical evaluation on the basis of the distribution of the Grade of oral mucositis, the Grade of oral mucositis in the PZ group was significantly lower than in the control group at 6 and 7 weeks (p=0.016, p=0.018).  The incidence of severe oral mucositis of Grade 3 was 15.0% (3 cases) in the PZ group and 41.7% (10 cases) in the control group at 6 weeks, and was 15.0% (3 cases) in the PZ group and 33.3% (8 cases) in the control group at 7 weeks.
Conclusion: These results suggest that PZ-CP oral rinse inhibits the aggravation of oral mucositis induced by CRT or promotes its healing.