Although obesity treatment primarily targets the gastrointestinal tract, the opportunities for endoscopists in Japan to be involved in obesity management are limited. Recently, various endoscopic bariatric and metabolic therapies (EBMTs) have been developed to overcome the limitations of conventional medical and surgical treatments. Among them, endoscopic sleeve gastroplasty is gaining global recognition as a reliable obesity treatment because of its minimally invasive nature compared to surgery and superior weight loss efficacy compared to pharmacotherapy. This review outlines the current trends in EBMTs that endoscopists should note, in the context of recently approved glucagon-like peptide-1 receptor agonists for obesity treatment.

EUS is a widely recognized, noninvasive imaging modality that enables high-resolution evaluation and is useful for the diagnosis of early chronic pancreatitis (ECP) and chronic pancreatitis (CP). However, low interobserver reliability in the EUS diagnosis of ECP and CP has long been a significant issue. Recent advances in ultrasound technology have enabled the use of elastography in EUS to assess tissue stiffness. In addition to conventional strain elastography, the introduction of shear wave elastography has made it possible to evaluate the degree of pancreatic fibrosis more objectively and quantitatively, thereby improving the reproducibility and accuracy of EUS diagnoses. Furthermore, recent developments in image processing have facilitated the measurement of ultrasound speed to optimize image construction conditions, and their utility in improving diagnostic accuracy has also been reported. These technological advances have made the diagnosis of ECP and CP more straightforward and objective. In particular, the early diagnosis of CP is extremely important for preventing progression to pancreatic cancer, and further development and standardization of EUS techniques are highly anticipated.

[Objective] Asymptomatic amebic colitis cases are sometimes observed. In this study, we investigated the endoscopic findings and clinical characteristics associated with asymptomatic patients.

[Methods] We enrolled 21 patients diagnosed with amebic colitis at a single institution between January 2012 and February 2024. The cases were divided into asymptomatic (9 cases) and symptomatic (12 cases) groups. We retrospectively compared clinical backgrounds, lesion distributions, endoscopic findings, and trophozoite detection rates using pathological or microscopic examinations between the two groups.

[Results] The clinical backgrounds of the two groups did not differ significantly. Rectal lesions were significantly less frequent in the asymptomatic group (11%) than in the symptomatic group (83%) (p=0.002). Cecal lesions were frequently observed in the asymptomatic group (89%). No significant between-group differences were observed in rates of endoscopic findings including aphthae, ulcers, white exudates, and erosions, as well as in trophozoite detection rates.

[Conclusion] In patients with asymptomatic amebic colitis, rectal lesions were less frequent, and cecal lesions were commonly observed. Pathological and microscopic diagnoses were equally useful in both asymptomatic and symptomatic cases.

A 69-year-old man was referred to the Department of Respiratory Medicine at our hospital after abnormal shadows were detected in his left lung during a medical check-up. Contrast-enhanced CT revealed a 76×34 mm mass in the left upper lobe, located cephalic to the aortic arch, adjacent to the esophagus, along with clustered enlargement of mediastinal lymph nodes. Biopsy was necessary to differentiate between pulmonary tuberculosis and malignancy. Although endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) was initially considered, the anatomical location was challenging. Therefore, the patient was referred to the gastroenterology deparfent for transesophageal EUS-FNA. The EUS was hypoechoic with clear borders and irregular margins. We performed FNA and found that the smear was positive for Ziehl-Neelsen staining and identified Mycobacterium tuberculosis based on nucleic acid amplification test positivity. The final diagnosis was pulmonary tuberculosis with associated tuberculous lymphadenitis.

The patient was a 75-year-old man who underwent elective sigmoid colectomy for repeated sigmoid colon torsion and subsequent transverse loop colostomy because of anastomosis leakage. As postoperative anastomotic stenosis was detected on a CS, endoscopic balloon dilation was performed thrice in stages, and the diameter was increased to 15 mm. Restenosis was observed within a short period, and dilation was repeated with an increased balloon diameter; however, perforation occurred. Conservative treatment improved the condition, but restenosis was observed in the subsequent CS after balloon dilation to Φ15 mm, triamcinolone was injected locally and prednisolone was administered orally. No restenosis was observed at the next follow-up, and the colostomy opening was closed successfully.

A 63-year-old man with suspected acute pancreatitis was admitted to our hospital. Computed tomography revealed a mediastinal pancreatic pseudocyst with a background of chronic pancreatitis. Pancreatography showed extraductal leakage of contrast medium into the cyst, leading to the diagnosis. After endoscopic nasopancreatic drainage, the mediastinal pancreatic pseudocyst shrank; therefore, a pancreatic duct stent was placed. Multiple pancreatic duct stent exchanges were performed to achieve spontaneous closure of the pancreatic duct collapse and stent removal. Here, we report the usefulness of endoscopic treatment of mediastinal pancreatic pseudocysts and discuss the literature.

EIS is an effective prophylactic hemostatic procedure for esophageal varices. However, injecting sclerosants into blood vessels can be technically challenging, and insufficient sclerosant injection is often observed. Gel immersion EIS (GI-EIS), which utilizes the gel immersion endoscopy technique, may facilitate sclerosant injection into blood vessels by maintaining a low intraluminal pressure with the gel, thereby expanding the varices. Additionally, this method may enhance endoscope stability during the procedure. This article introduces the GI-EIS procedure and provides technical tips for its successful implementation.

The endoscopic unroofing technique, an endoscopic treatment for gastrointestinal submucosal tumors, involves partial resection (approximately one-third to one-half) of the upper portion of the tumor using a snare, which allows the residual tumor to detach spontaneously over time. This method is associated with a low risk of complications such as bleeding or perforation. In the cases of gastrointestinal lipomas that can cause gastrointestinal bleeding or intussusception, unroofing after strangulation of the tumor base with a snare loop enables both histological diagnosis and curative treatment while also minimizing the risk of perforation. This technique is a minimally invasive procedure that can be performed safely within a short period of time.

Objectives: Colonoscopy (CS) is an important screening method for the early detection and removal of precancerous lesions. The stool state during bowel preparation (BP) should be properly evaluated to perform CS with sufficient quality. This study aimed to develop a smartphone application (app) with an artificial intelligence (AI) model for stool state evaluation during BP and to investigate whether the use of the app could maintain an adequate quality of CS.

Methods: First, stool images were collected in our hospital to develop the AI model and were categorized into grade 1 (solid or muddy stools), grade 2 (cloudy watery stools), and grade 3 (clear watery stools). The AI model for stool state evaluation (grades 1-3) was constructed and internally verified using the cross-validation method. Second, a prospective study was conducted on the quality of CS using the app in our hospital. The primary end-point was the proportion of patients who achieved Boston Bowel Preparation Scale (BBPS) ≥6 among those who successfully used the app.

Results: The AI model showed mean accuracy rates of 90.2%, 65.0%, and 89.3 for grades 1, 2, and 3, respectively. The prospective study enrolled 106 patients and revealed that 99.0% (95% confidence interval 95.3-99.9%) of patients achieved a BBPS ≥6.

Conclusion: The proportion of patients with BBPS ≥6 during CS using the developed app exceeded the set expected value. This app could contribute to the performance of high-quality CS in clinical practice.

The Japanese Association for Capsule Endoscopy has developed the “Clinical Practice Guidelines for Capsule Endoscopy” according to evidence-based medicine, following the “Minds Manual for Guideline Development 2020 ver. 3.0.” Capsule endoscopy (CE) enables minimally invasive examination of the digestive tract lumen. In Japan, CE for the small intestine has been covered by national health insurance since 2007. Reimbursement for CE of the colorectum in Japan was approved in 2014. Currently, CE is indicated for the small intestine and colorectum. These guidelines consist of clinical questions (CQs), background questions (BQs), and future research questions (FRQs). Some CQs are based on expert consensus due to limited high-level evidence.

These guidelines provide clinical guidance on the use of small intestine CE, colon CE, unapproved CE, patency capsule, endoscopic capsule delivery, reading supports, and CE in out-of-clinic settings.