(Background and Aim) We investigated the short-term outcomes of per-oral endoscopic myotomy (POEM) in patients with an esophageal functional disorder at our institution.

(Method) We retrospectively evaluated 16 cases of POEM, which were performed from October 2018 to December 2019. Surgical outcomes and efficacy were assessed.

(Results) There were 16 patients:12 with esophageal achalasia (EA), 3 with jackhammer esophagus (JE), and 1 with esophagogastric junction outlet obstruction (EGJOO). The median procedure time was 91 (65–196) min, and the median muscle layer dissection was 8.0 (5–21) cm. There were no severe adverse events. Following the procedure, symptoms were significantly improved (Eckardt score, median 5.5→1.5, p = 0.005; F scale, median 21.0→11.0, p = 0.004). Two months later, high-resolution manometry was performed on 13 patients. In 9 cases of EA and 1 case of EGJOO, the median integrated relaxation pressure was significantly decreased (29.6→10.1 mmHg, p < 0.005). In 3 cases of JE, the median distal contractile integral was improved (8831.4→849.2 mmHg/s/cm).

(Conclusions) Initial experience at a single institution showed that POEM was feasible, safe, and appeared effective. Accumulation of cases and assessment of long-term outcomes would be desired.

Purpose: Chronic gastritis caused by persistent Helicobater pylori (HP) infection is the greatest known risk factor for gastric cancer (GC). However, with an increasing number of patients undergoing HP eradication, the incidence of post-eradication cancer is also increasing. The aim of this study is to clarify the characteristics of post-eradication GC.

Methods: This is a single-center retrospective study on all cases of GC that underwent endoscopic submucosal dissection (ESD) at our hospital between 2013 and 2018. Characteristics of post-eradication and HP-positive GC were compared.

Results: Of a total of 1186 cases of GC, 165 (13.9%) were post-eradication GC and 243 (20.5%) were HP-positive GC. Multivariable analysis showed that compared to HP-positive GC, post-eradication GC comprised a higher rate of depressed lesions (67.9 vs 49.4%, p = 0.003), and demonstrated a smaller tumor size (13.4±9.7 vs 17.1±10.4 mm, p = 0.036), and longer operative time (115.0±69.9 vs 110.7±65.3 minutes, p = 0.004). There was no significant difference in resection diameter (37.4±13.0 vs. 40.9±12.5 mm, p = 0.551).

Discussion: Post-eradication GC is detected at a smaller stage than HP-positive GC. The operation time, may have become longer in post-eradication GC due to the difficulty in diagnosing the extent of the lesion.

[Background] Although various methods have been used to make colorectal ESD a less invasive procedure, perforation sometimes occurs. [Purpose] The purpose of this study was to examine the clinical course of patients with colorectal ESD perforation in our hospital. [Subjects/methods] Of the 1780 colorectal lesions resected by ESD in our hospital from April 2005 to December 2019, 40 lesions in 40 cases with perforation were retrospectively examined. RESULTS: Of the 40 cases with perforation, intraoperative perforation was found in 29 cases (1.7%), and delayed perforation was found in 11 cases (0.6%). Out of 29 cases with intraoperative perforation, 25 cases were able to complete the excision of lesions, and 4 cases were interrupted with surgical operation performed on another day. Abdominal findings were aggravated in 3 of the 25 patients who received conservative treatment, and emergency surgery was performed. In 11 cases with delayed perforation, 5 cases were diagnosed on the 1st and 2nd days after surgery, and 1 case was diagnosed on the 5th day. Of the 11 cases, emergency surgery was necessary in 5 cases, which was a high rate compared with intraoperative perforation. [Conclusion] Compared with intraoperative perforation, delayed perforation often requires emergency surgery. The prevention of delayed perforation is a future issue.

We evaluated clinico-endoscopic features and clinical outcomes in 38 consecutive patients with acute hemorrhagic rectal ulcer (AHRU) among 364 patients with lower gastrointestinal bleeding. Subjects with AHRU consisted of 20 men and 18 women with a mean age of 77 years. As compared AHRU group and non-AHRU group regarding clinical features, the rate of high PS (≥ 3) was significantly higher in the AHRU group. Twenty patients (52.6%) underwent endoscopic hemostasis, and 18 patients (44.7%) underwent conservative treatment. Re-bleeding was observed in 29%, and 11 cases with re-bleeding and 27 cases without re-bleeding were compared and examined using univariate analysis, but there was no significant difference. Deaths totaled 9 (24%) during hospitalization, and the main cause of death was exacerbation of the primary and co-morbid conditions. There was no significant difference between the 9 death cases and 29 non-death cases in the comparative study by univariate analysis. The number of patients with AHRU was significantly higher in PS3 or higher than in non-AHRU, due to severe cases. There are many cases of death due to exacerbation of underlying diseases and comorbidities. Therefore, management of AHRU should focus on not only controlling the local bleeding but also managing the comorbidities and complications.

When hemorrhagic duodenal ulcers are untreatable by endoscopy, alternatives are surgery or intravascular treatment. However, if the patient's condition is unfavorable, these options are occasionally unavailable. We report 2 cases in which Over-the-Scope clip (OTSC) was used in place of surgery or intravascular treatment. Case 1: An 82-year-old man, admitted with postrenal failure and renal carcinoma, suffered from persistent duodenal ulcer hemorrhaging. Endoscopic hemostasis was required 6 times; therefore, OTSC was used for endoscopic closure of the duodenal ulcer. No re-bleeding occurred after treatment. Case 2: A 79-year-old man with a history of cerebral infarction and idiopathic thrombocytopenic purpura visited the ER because of tarry stools. He was diagnosed with a hemorrhagic duodenal ulcer; however, the muscle layer was partially defective. Therefore, endoscopic suturing was performed with OTSC. No adverse event occurred after treatment. The OTSC, which can grab the target mucosa more strongly and widely than conventional clips, can be an alternative when hemorrhages cannot be controlled by conventional treatments.

It is necessary to simplify the procedure of endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) and improve its safety.

An 84-year-old female with jaundice was referred to our hospital. Contrast-enhanced computed tomography and endoscopic biopsy revealed pancreatic head cancer and resulting obstructive jaundice. We performed endoscopic retrograde cholangiopancreatography, but biliary drainage was difficult due to duodenal invasion of pancreatic cancer. Therefore, EUS-HGS using the double guidewire technique was performed. In the usual procedure, the fistula is expanded using a dilator or balloon and then a second guidewire is inserted and placed. However, we simplified the double guidewire technique of EUS-HGS by dilating the fistula and placing the second guidewire using an uneven double lumen catheter. After performing EUS-HGS, the patient recovered from obstructive jaundice and was discharged on the 18th hospital day.

We retrospectively investigated the clinical outcomes of endoscopic esophageal foreign body removal. The study included 26 patients diagnosed with esophageal foreign bodies at Nihon University Hospital between October 2015 and February 2020. Esophageal foreign bodies included food loaves (n=10), press-through packages (n=8), fish bones (n=5), dental prostheses (n=2), and drugs (n=1).

Foreign bodies were endoscopically removed in all patients. Esophageal injury secondary to the aforementioned sharp objects occurred in five patients. Sharp objects such as fish bones, dental prostheses, and press-through packages may injure the esophageal mucosa; therefore, it is important to perform pretreatment imaging using modalities such as computed tomography to rule out perforation.

Endoscopic treatment was useful for foreign body removal in all patients in this study.

Keeping biscous lidocaine solution in the hypopharynx and repeating gargling (group-A) has been used as pharyngeal anesthesia of esophagogastroduodenoscopy in our hospital for many years. Spraying lidocaine spray to the hypopharynx (group-B) is an option with lower risk of aspiration and less physical difficulty. Anesthetic effects should be compared in both methods. Subjects who underwent esophagogastroduodenoscopy were randomly assigned to either group-A or -B. A series of questionnaire survey was set before and after the examination, and the physical and mental stress was evaluated subjectively (i: discomfort during pharynx passage, ii: coughing during the examination, iii: anxiety about the next examination), and objectively. A univariate analysis of the evaluation about the stress caused by esophagogastroduodenoscopy showed no significant difference between group-A (71 cases) and group-B (70 cases). Group-B provided the equivalent anesthesia effect as group-A. It was considered that the physical and mental stress during esophagogastroduodenoscopy was greatly affected by the anxiety before the examination.

Here we report a man in his 60s who underwent surgery for hypopharyngeal cancer 14 years previously, and has since received a combination of endoscopic submucosal dissections (ESDs), CRT and photodynamic therapy (PDT) for metachronous multiple esophageal cancers. His latest esophagogastroduodenoscopy showed mild stenosis and scarring, but no abnormalities, indicating his long-term disease-free status. After CRT, PDT can be currently available for esophageal cancer cases with ineligible factors of ESD and/or surgical resection, such as tumor depth, patient comorbidities and age. PDT was efficacious and minimally invasive for a treatment of superficial esophageal cancer in our inoperable case. Combination of ESD and PDT after CRT, minimally invasive tools, may be good multimodality therapy for metachronous superficial esophageal cancers difficult-to-treat by surgery.

Background

The prevalence of ectopic gastric mucosa (EGM) is approximately 11–14.2%. Most EGMs are clinically insignificant;however, they are occasionally known to harbor esophageal cancer.

Case

Case 1 was a 64-year-old man diagnosed with esophageal cancer in the EGM, UtCe Type0-IIa tub1 cT1b-SM1 (N0M0) cStageI. We performed endoscopic submucosal dissection (ESD) for diagnostic and therapeutic purposes. Pathological examination revealed a well-differentiated adenocarcinoma arising from the EGM.

Case 2 was a 47-year-old man diagnosed with CeUt Type0-IIa SCC cT1-MM (N0M0) cStageI. His lesion was sandwiched between two EGMs. It was thought that the lesion might have extended to the EGM. We performed ESD on one of the EGMs to confirm this hypothesis. Pathological examination revealed a squamous cell carcinoma. No lesion was found in the EGM;however, the tumor was present on the borderline of the EGM.

Conclusion

We report two cases of esophageal cancer arising from or within EGM treated using ESD. The patients recovered after ESD and did not require further treatment.

A 62-year-old male was admitted to hospital the limb sensation and a weakness in the main complain. He had an emergency upper gastrointestinal endoscopy because a result of his blood test was severe anemia, Hb 4.9 ml/dL.

The endoscopy showed a hemorrhagic gastric ulcer with a huge exposed vessel.

On treatment with IVR, it was difficult for us to insert a catheter in his vessel because his vessels have abnormal running vessels. Therefore, we decided to insert an intra-aortic balloon occlusion (IABO) catheter on treatment with endoscopy. The IABO helped to control the ulcer bleeding and made an easier for us to complete an endoscopic hemostasis with coagulation.

Gradually over a period of two months, the ulcer was healed to normal mucosa. Such as this case, it is suggested that IABO is able to be completed an endoscopic hemostasis for a case that be predicted difficulty to hemostasis.

The present case was of a 79-year-old man who underwent left nephrectomy for renal cell carcinoma (RCC) 14 years prior. Signs of anemia were observed, prompting an exploratory upper gastrointestinal endoscopy to search for the origin. The anemia was attributed to a hemorrhagic, tumorous lesion discovered in the fornix (size: ~30 mm). Endoscopic mucosal resection was performed to control the anemia. The patient was diagnosed with metastatic gastric cancer secondary to RCC, based on the abundance of clear-cell carcinoma cells in his pathological specimens, which resembled his surgical specimens taken 14 years prior. Late recurrence is not uncommon in RCC, and discoveries of gastric metastasis are often prompted by gastrointestinal bleeding. Such trends mean that clinicians should keep RCC in mind during a patient's examination and treatment if a hemorrhagic lesion (s) is observed in the stomach, even if a long time has passed since the diagnosis of RCC.

A 72-year-old man was admitted to our hospital because of gastric mucosal irregularity on gastroscopic examination. He was successfully treated for Helicobacter pylori infection at the age of 63 years. Blood examinations, including tumor markers, revealed normal results. Upper gastrointestinal endoscopy revealed a large 0-IIc lesion measuring 10 mm in the gastric body. The biopsy revealed atypical glands. Enhanced computed tomography revealed no metastasis to the lymph nodes or other organs. Therefore, a diagnosis of early gastric cancer was made and endoscopic submucosal dissection (ESD) was performed. The biopsy specimen revealed gastric carcinoma with lymphoid stroma on hematoxylin and eosin staining, Epstein-Barr encoding region in situ hybridization revealed that tumor cells were positive for Epstein-Barr virus (EVB). Hence, the patient was diagnosed with EBV-associated carcinoma with lymphoid stroma.

Here, we have reported a case of EBV-associated carcinoma with lymphoid stroma that was diagnosed using ESD.

A 22-year-old woman who had abdominal pain and diarrhea from 5 days ago got a CT scan in the hospital of origin and had a tumor about 5 cm in the stomach and bleeding. Upper gastrointestinal endoscopy revealed a large gastric submucosal tumor in pylorus. We considered it a malignant gastric submucosal tumor, and performed surgery, it was diagnosed as gastric plexiform fibromyxoma. Gastric plexiform fibromyxoma is a rare gastric mesenchymal tumor first reported by Takahashi et al. in 2007. Gastric plexiform fibromyxoma usually causes nonspecific symptoms of bleeding signs and is often operated on for that reason. However, surprisingly, plexiform fibromyxoma is a benign tumor with no reports of metastasis or recurrence.

A 73-year-old man was admitted with vomiting and left costal pain.

He had undergone pylorus-preserving gastrectomy with B-1 reconstruction and was recently eating many persimmons. Physical examination revealed tenderness in the upper abdomen and left-side ribs. Abdominal CT showed a mass containing air in the gastroduodenal anastomosis. Esophagogastroduodenoscopy revealed a bezoar of about 10 cm in diameter in the remnant stomach. It was difficult to crush the bezoar with a grasping forceps and snare. Coca-Cola was locally injected, which softened the bezoar. We could then crush the bezoar with the grasping forceps and snare, and removed the bezoar. Oral administration or nasogastric lavage of Coca-Cola were reported as treatments for bezoars. In our case, the treatment time of a bezoar was significantly shortened by local injection of Coca-Cola and the bezoar could be treated with a small amount of Coca-Cola compared with that in previous reports.

A 90-year-old female was admitted to our hospital with hematemesis. Esophagogastroduodenoscopy revealed blood flowing from a submucosal tumor of about 20 mm in diameter with a few erosions on its surface at the greater curvature of the antrum. It was bleeding from one of the erosions and treated by electrocoagulation. The submucosal tumor had initially been detected by esophagogastroduodenoscopy four years previously and was presumed to be a lipoma by computed tomography. To prevent rebleeding, the ESD procedure was performed on the 5^th hospital day with the patient's consent. Complete en bloc resection was achieved in 70 min. There were no specific technical difficulties or complications. Pathological examination confirmed that the submucosal tumor was a lipoma. To our knowledge, this is the first report of a hemorrhagic gastric lipoma removed by ESD in a patient in her nineties.

A 75-year-old man was referred to our hospital with suspected gastric cancer. Endoscopy revealed a 10 mm-sized, reddish, depressed lesion in the middle gastric body. Biopsy tissue suggested a poorly differentiated adenocarcinoma. Since submucosal invasion could not be ruled out, the patient underwent laparoscopic distal gastrectomy. Resected specimen showed a poorly differentiated adenocarcinoma with significant lymphocytic infiltrate, and 390 μm of submucosal invasion. There was no lymph node metastasis or lymphovascular invasion. Epstein-Barr virus-encoded RNA in situ hybridization was positive, and the diagnosis of Epstein-Barr virus-associated gastric carcinoma with lymphoid stroma (GCLS) was made. GCLS has a low incidence of lymph node metastasis and a relatively good prognosis. In this case, if we had diagnosed GCLS preoperatively, endoscopic submucosal dissection may have been an option for treatment.

We report a case of a hyperplastic polyp that underwent malignant transformation after eradication therapy. The patient was a 76-year-old man who had a 15-mm sized polyp in the fornix of the gastric body. Histologic examination of a biopsy specimen revealed that the lesion was a hyperplastic polyp. Helicobacter pylori infection was confirmed by examining Helicobacter pylori antibodies. After eradication therapy for five months, the polyp decreased to 10 mm in size. After eradication therapy for fourteen months, endoscopy revealed that the polyp had significantly decreased in size, but was accompanied by a localized erosion (IIa+IIc), and biopsy examination showed Group V. Total gastrectomy was performed and the diagnosis of hyperplastic polyp with malignant transformation was confirmed histologically. Our clinical experience and lessons from this case are discussed.

In our hospital, percutaneous transesophageal gastro-tubing (PTEG) has been performed for patients with dysphagia in whom percutaneous endoscopic gastrostomy (PEG) would be challenging. We herein report a patient with a high risk of self-removal of the PTEG tube in whom percutaneous endoscopic duodenostomy (PED) was performed. A 62-year-old woman suffered cerebral infarction. She had undergone distal gastrectomy and Billroth-I reconstruction (BI) for early gastric cancer at the age of 56 years. PEG was not performed because the gastric remnant was found below the costal arch by transillumination. Instead, PED was performed by the pull method. PED and PTEG each have advantages and disadvantages. Hence, it is necessary to select the appropriate nutrition route depending on the characteristics of each case.

A 72-year-old man, having a past history of H. pylori eradication 7 years ago, underwent esophagogastroduodenoscopy (EGD) at a clinic. A depressed lesion on the gastric angle was detected and its pathological diagnosis was adenocarcinoma. Magnifying endoscopy with NBI (ME-NBI) demonstrated that the red depression, 20×8 mm in diameter, had regular microvascular/microsurface patterns, and the diagnosis was noncancer. Endocytoscopy (ECS), an ultra-magnifying endoscopy, showed that a part of the lesion had high-grade ECS atypia, and the diagnosis was cancer. The pathological diagnosis of the ESD specimen was 0-IIc, 3 mm, tub1, pT1a. H. pylori-eradicated cancers are often covered with epithelium with low grade atypia, which causes the difficulty of endoscopic diagnosis. In this case, ME-NBI could not show cancerous findings, but ECS could demonstrated cancerous findings, suggesting that ECS may be useful in the diagnosis of H. pylori-eradicated cancer.

A 60-year-old man was successfully eradicated 5 years ago for Helicobacter pylori infection. In April 20XX, upper gastrointestinal endoscopy (EGD) showed mild gastric atrophy (C1) and a small erosion in the gastric antrum. In July of the same year, biopsy of the lesion was performed, and was diagnosed as signet-ring cell carcinoma. He was referred to our hospital, and the diagnosis of endoscopic work-up was early gastric cancer; 6 mm, 0-IIc, sig, cT1a, UL-. The 4-point biopsy was negative for cancer, and endoscopic submucosal dissection (ESD) was performed. The pathological result was noncurative resection; adenocarcinoma (por2> sig), pT1b2 (900 μm), pUL0, Ly0, V0, pHM0, pVM1. Thus, distal gastrectomy was additionally done. The postoperative pathological result was scirrhous gastric cancer with extensive cancer invasion in the muscularis propria centering on the ESD scar. As shown in this case, we need to keep in mind that poorly differentiated adenocarcinoma can develop in the Helicobacter pylori-eradicated gastric mucosa with mild atrophy without intestinal metaplasia.

An 87-year-old man was diagnosed with ampullary adenoma based on an upper gastrointestinal endoscopy screening. Endoscopic papillectomy was recommended, but the patient refused. Six years later, he visited the hospital presenting with symptoms of cholangitis, and an upper gastrointestinal endoscopy revealed an enlarged ampullary tumor. We performed a biopsy and diagnosed the patient with an adenocarcinoma. Since he did not agree to a surgery, we performed palliative endoscopic biliary drainage using a self-expandable metallic stent (SEMS).

The origin of the ampullary adenoma remains unclear. We experienced a case in which an adenoma developed into cancer over a long period of 6 years. We will eventually report the case along with a review of literature.

An 84-year-old man was admitted to our hospital with anemia. He had undergone right nephrectomy for renal cell carcinoma (RCC) 5 years ago. Upper gastrointestinal endoscopy revealed a protuberance with oozing hemorrhage in the descending part of the duodenum. Visceral angiography identified extravasation from a branch of the gastroduodenal artery (GDA). Coil embolization was performed on two branches of the GDA, and progression of anemia slowed down. After 2 months, he died from renal dysfunction and an autopsy was performed. Results showed metastasis from RCC in the descending part of the duodenum, myocardium, pancreas, and both lungs. Duodenal metastasis from RCC is mostly diagnosed in the wake of a bleeding episode, and sometimes presents as a submucosal tumor.

A 70-year-old asymptomatic man presented with a growing submucosal tumor in the duodenal bulb; and despite two EUS-FNA procedures, a diagnosis could not be confirmed. Since the mass was stalked and enlarged to 40 mm in size, the patient underwent endoscopic resection with grasping scissor forceps, while traction was applied for diagnostic treatment, considering the risk of gastrointestinal obstruction. The pathological diagnosis was Brunner's gland hyperplasia, and the patient was followed up with annual upper gastrointestinal endoscopy. Here, we report a case of endoscopic resection of a large duodenal submucosal tumor using a traction device.

A woman in her 80s underwent surgery for ascending colon cancer about four years ago; she had a positive surgical margin. However, chemotherapy was not given according to the patient's wish. Abdominal computed tomography three years after surgery revealed a mass lesion in the descending part of the duodenum. A submucosal (mesenchymal) tumor was suspected on endoscopic ultrasonography. However, endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) cytology revealed adenocarcinoma, with findings similar to pathological findings at the time of surgery four years earlier. The patient was therefore diagnosed with a duodenal recurrence of her prior ascending colon cancer. EUS-FNA is minimally invasive and is useful for the diagnosis of tumor-like lesions in the submucosa.

A 65-year-old man taking dual antiplatelet therapy (DAPT) on maintenance dialysis for chronic renal insufficiency was rescued to our hospital by chief complaint of bloody stool in 2019. Contrast-enhanced CT showed extravasation of the contrast agent into the ileum, and he was hospitalized with a diagnosis of small intestinal bleeding. Blood stool disappeared after discontinuation of DAPT. Small intestinal endoscopy revealed a 25 mm-sized polyp with erosion in the ileum, which was considered a bleeding source. Based on the risk of rebleeding due to DAPT resumption, EMR was performed, and Peutz-Jeghers type polyp was diagnosed. With the aging, the number of patients taking DAPT is expected to increase. Small intestinal polyps, which had previously been asymptomatic, may cause gastrointestinal bleeding due to oral administration of DAPT, which may increase the frequency of detection. In gastrointestinal bleeding from the small intestine of patients receiving DAPT, it was considered important to remind bleeding from polyps such as in this case.

In 2012, treatment using Self-Expandable Metallic Stent (SEMS) for colorectal cancer bowel obstruction started being covered under insurance in Japan. In addition to being effective for Bridge To Surgery (BTS), the use of SEMS involved a good success rate and symptom improvement rate. We analyzed 11 patients (seven men and four women, average age; 70 years) for whom SEMS insertion was performed at our hospital for BTS from January 1, 2016 to December 31, 2018.

The stenosis site was the transverse colon in four patients, the descending colon in four patients, and the sigmoid colon in three patients. All cases of SEMS insertion were successful. The colon obstruction score improved in all patients, and primary anastomosis became possible. In addition to the high safety and good short-term results of metal stenting for BTS, there was no statistically significant difference in reports comparing long-term prognosis with emergency surgery. These results suggest that the use of SEMS for BTS is effective in the treatment of malignant colorectal stenosis.

61-year-old woman. She was in remission for ulcerative colitis with mesalazine, azathioprine and infliximab treatment. Psoriasiform dermatitis developed 3 years after the administration of infliximab, and it was diagnosed as a paradoxical reaction due to anti-TNF-α antibody therapy. After switching from infliximab to vedolizumab, psoriasiform dermatitis was markedly improved. In the treatment of intractable psoriasiform dermatitis, changing to a molecular target agent with a different mechanism of action could be considered as one of therapeutic options.

A 70-year-old man with bloody stools was emergently transported to our hospital by ambulance. Abdominal/pelvic CT with contrast revealed blood extravasation in his transverse colon, and he was hospitalized due to suspected colonic diverticular bleeding. Lower gastrointestinal endoscopy revealed a diverticulum with erosion and redness in the transverse colon. The diverticulum was thought to be the responsible lesion, and endoscopic band ligation (EBL) was performed. After EBL, an exposed vessel was found in the inverted diverticulum. Endoscopic findings of active hemorrhage, non-hemorrhagic exposed vessels, or adherent blood clot are indications for hemostasis of colonic diverticular bleeding. Diverticular bleeding in which the inside of the responsible diverticulum cannot be observed by endoscopy, would be a good indication for EBL because it would be difficult to perform clip hemostasis through the direct approach.

Colonoscopy is very useful for diagnosing and treating colorectal diseases. Bowel preparation with polyethylene glycol (PEG) or magnesium citrate has been widely performed and is considered to be safe, but it can sometimes cause severe electrolyte disturbances.

A 74-year-old man was admitted to our hospital for a planned colonoscopy. He had no history of neurological diseases. He was taking no medications. He was given oral administration of 1.8 L magnesium citrate. While he was waiting to undergo colonoscopy, he began to respond slowly and consciousness disorder developed. Brain computed tomography showed no abnormalities. Laboratory examination showed a serum sodium level of 119 mEq/L. He was diagnosed with severe symptomatic hyponatremia and treated with hypertonic saline infusion. Colonoscopy was cancelled. The next day, the sodium level increased to 127 mEq/L and his consciousness level recovered to normal. If a patient shows neurological disturbance at the time of colonoscopy, serum electrolytes should be checked and treatment should be started promptly.

A 57-year-old man, who was administered methotrexate for rheumatoid arthritis seven years prior, experienced lower abdominal pain and diarrhea for one year; therefore, he visited our hospital for further examination. Colonoscopic examination revealed an Is-type polyp in the anal side of the ileocecal valve and Is-like elevated lesion in the ascending colon, which were then removed endoscopically. Narrow-band imaging revealed a type II open pit pattern like in the center of the lesion and a type V_N pit pattern like in the periphery of the lesion. The former histopathological findings indicated low-grade tubular adenoma; the latter indicated early colonic cancer with submucosal invasion in the peripheral lesion and a hyperplastic polyp with a serrated pattern in the center of the lesion in the ascending colon. He is currently undergoing regular follow-up.

We report 3 cases of juvenile polyps treated with endoscopic resection. The first case was a 30-year-old man with a 1-week history of lower abdominal pain; hence, he was transferred to our hospital. Colonoscopy revealed a pedunculated polyp in the sigmoid colon. The polyp was removed endoscopically and was histologically diagnosed as a juvenile polyp. The second case was a 41-year-old man who presented to our hospital with a 1-month history of bloody stools. Colonoscopy revealed a pedunculated polyp in the sigmoid colon. The polyp was removed endoscopically and was histologically diagnosed as a juvenile polyp. The third case was 55-year-old woman who presented to our hospital with a 1-month history of lower abdominal pain and mild diarrhea. Colonoscopy revealed a pedunculated polyp in the sigmoid colon. The polyp was removed endoscopically and was histologically diagnosed as a juvenile polyp. Their symptoms were improved before colonoscopic examination.

A woman in her 60s was referred to our hospital with a suspicious finding of obstructive transverse colon cancer. Contrast-enhanced CT also revealed multiple lung, liver, and ovarian metastases, resulting in the diagnosis of cT4aN1bM1c2 cStage IVc obstructive colorectal cancer. Adhesion by huge ovarian tumor and hyperextension of sigmoid colon made it difficult to observe the front view of the transverse colonic tumor by conventional colonoscopy. Therefore, short-type double-balloon enteroscopy was used and enabled us to place colonic stent safely and easily. We underwent primary and ovarian tumors resection without stoma creation. Systemic chemotherapy with bevacizumab was introduced after a good postoperative course. The double-balloon enteroscopy is useful to place colonic stent in a difficult case with conventional colonoscopy.

A 45-year-old man visited our hospital for unrelenting abdominal pain since the day before presentation. Physical examination showed right upper abdominal tenderness. Blood tests revealed evidence of an inflammatory response; however, no other abnormalities were detected. Computed tomography revealed intussusception (telescoping of the small intestine into the ascending colon). A cystic lesion was detected near the root of the appendix in the advanced region. We performed colonoscopy, which revealed a submucosal tumor in the vicinity of the hepatic curve in the advanced region, and we performed ileocolic resection. Histopathological examination of the resected specimen showed an edematous lesion with inflammatory cell infiltration, and we also observed a submucosal abscess. Previous studies have reported that approximately 50% of the lesions were malignant, and 90% of patients underwent operation in cases of cecal intussusception. We report a rare case of intussusception secondary to a cecal submucosal abscess.

Here we report a 74-year-old man with squamous cell lung cancer who was administered pembrolizumab. The patient was admitted to our hospital because of frequent diarrhea and abdominal pain after 31 cycles of pembrolizumab. Given the clinical, radiological, endoscopic, and pathological findings, the patient was diagnosed with irAE colitis. The patient's symptoms improved with prednisolone after cessation of pembrolizumab. However, he developed aspiration pneumonia. After cessation of prednisolone and treating with antibiotics, he had pseudomembranous colitis and CMV colitis. Both metronidazole and ganciclovir were initiated. Then irAE colitis had recurred and oral 5-ASA was administered. Thereafter, the patient's general condition has improved and colonoscopy showed a slight rough mucosa but improved visible vascular pattern 6 months after the treatment of 5-ASA.

An 86-year-old female visited an emergency department for epigastric pain and fever. She had received Billroth II gastrectomy due to gastric cancer 32 years ago. Laboratory tests revealed elevated levels of hepatobiliary enzymes. Computed tomography showed a common bile duct stone with a diameter of 20 mm. We performed endoscopic retrograde cholangiopancreatography. In the first session, endoscopic needle-knife sphincterotomy under the biliary stent was performed. In the second session, stone removal was completed after endoscopic papillary large balloon dilation. There were no complications associated with the procedure.

We successfully performed endoscopic papillary large balloon dilation with endoscopic sphincterotomy in a patient with previous Billroth II gastrectomy.

A 72-year-old man, with a history of proton beam therapy, transcatheter arterial chemoembolization (TACE), and radiofrequency ablation for hepatocellular carcinoma (HCC), presented to the emergency department of a hospital with abdominal pain and jaundice. Contrast-enhanced computed tomography revealed dilated intrahepatic bile ducts and hyperdense contents in the common bile duct. Endoscopic retrograde cholangiopancreatography (ERCP) revealed hemobilia, although the source of bleeding could not be detected because of multiple blood clots. He was referred to our hospital, and we performed contrast-enhanced magnetic resonance imaging and angiography. However, we could not identify the bleeding source; therefore, he was followed up. Four months later, he was readmitted to our hospital for abdominal pain. A second ERCP was performed, which revealed a filling defect in the left hepatic duct. Peroral cholangioscopy showed a polypoid lesion in the left hepatic duct, which bled easily on contact. The mass was considered to be the cause of hemobilia. Biopsy was performed, and the pathological analysis led to the diagnosis of a bile duct tumor thrombus of HCC. He underwent TACE, and recovered without recurrence of hemobilia.