Collagenous colitis (CC) is a disorder characterized by non-bloody chronic diarrhea and thickening of the subepithelial collagen band, and it is usually diagnosed by histological examination of biopsy specimens. CC and lymphocytic colitis (LC) are two subtypes of microscopic colitis (MC). In Western nations, the incidence of LC is slightly higher than that of CC. The incidence of MC increased during the 1980ʼs and 1990ʼs; however, it has become stable thereafter. Although the etiology of MC is not yet evident, it is considered to be a multifactorial disorder. Use of a nonsteroidal anti-inflammatory drug (NSAID) and/or proton pump inhibitor (PPI) has been shown to increase the risk of developing CC by case-control studies, and recently the role of PPIs has attracted attention.

In Japan, reported cases of CC increased after 2000, although the frequency is far less than that in Western nations. Most of the CC cases are associated with the use of PPI (especially lansoprazole) or NSAID. Furthermore, there are very few reported cases of LC in Japan. Concerning MC, many discrepancies exist between nations.

Originally, the endoscopic findings of patients with CC have been described as normal; however, endoscopic abnormalities have been reported to be common. Endoscopic findings of patients with CC are summarized as follows: 1) Changes in color: erythema, red spots, discoloration, etc. 2) Changes in vascular pattern: diminished vascular pattern, crowded vascular pattern, etc. 3) Changes in surface property: edema, friability, rough surface, granular surface, pseudomembranes, mucosal tears (linear ulcers/scars, “cat scratch”, crack-like grooves, etc.). 4) Other findings: loss of haustration.

In drug-associated CC cases, discontinuation of the suspected drug is usually followed by recovery from diarrhea. Our understanding of the pathophysiology of MC is still not satisfactory. The cause of the heterogeneity of MC is expected to be elucidated.

Fecal immunochemical test followed by colonoscopy is used for colorectal cancer screening throughout the world. Nowadays, colon capsule endoscopy (CCE) might be an alternative to colonoscopy, due to infrequent complications associated with CCE. According to the latest reports, the sensitivity of CCE for colon polyp ≥6mm is 84-94%, and its specificity is 64-88%. Diagnostic performance of CCE is superior to that of computed tomography (CT) colonography, and almost equivalent to that of colonoscopy. However, several issues remain to be addressed. In Japan, health insurance coverage for CCE is limited to patients in whom colonoscopy may be difficult. The medical expense of CCE is still too high. Patients must take a large amount of lavage solution. Because of these obstacles, CCE is not commonly performed in Japan. In February 2018, the Japanese Association for Capsule Endoscope (JACE) recommended the CCE regimen using castor oil, which may lead to increased performance of CCE. It is expected that the health insurance coverage for CCE will become the same as that for colonoscopy. As for management of inflammatory bowel disease, CCE might play an active role in assessing inflammation.

We retrospectively examined the incidence of bacteremia in patients with cholangitis caused by common bile duct stones who underwent endoscopic retrograde cholangiopancreatography at our hospital. We found bacteremia concomitant with cholangitis in 85 (35.2%) of the 241 patients. The incidence of bacteremia increased with the severity of cholangitis and reached as high as 65% among severe cholangitis cases. Extended-spectrum beta-lactamase-producing bacteria, which are a type of resistant bacteria and a cause of bacteremia, were also observed in three critical patients. Such patients would need to undergo prompt biliary drainage along with potent antibacterial therapy.

An 80-year-old man who was administered ramucirumab (RAM) as a second-line chemotherapy for advanced gastric cancer with lung metastasis, complained of melena and anemia after eight courses of chemotherapy. Capsule endoscopy revealed bleeding from the upper jejunum, and we diagnosed hemorrhagic small bowel angioectasia on subsequent single-balloon endoscopy. The anti-angiogenic effect of RAM may inhibit hemostasis. The bleeding was controlled by precise endoscopic intervention. Careful follow-up is important because of the high rebleeding rate of small intestinal vascular lesions including angioectasia.

A 92-year-old man was hospitalized for recurrent sigmoid colon volvulus. He had suffered six previous episodes of sigmoid colon volvulus in the past nine months. He was deemed unfit for surgery because of severe dementia, and he was treated with endoscopic decompression four times and with endoscopic detorsion two times for the six previous episodes. During the hospital admission for the seventh episode of sigmoid colon volvulus, although endoscopic findings revealed severely ischemic mucosa, the patient recovered after endoscopic decompression was performed. He was treated with percutaneous endoscopic colostomy (PEC) in order to prevent future recurrence of sigmoid colon volvulus. He experienced no procedural complications and had no recurrences of sigmoid colon volvulus in the subsequent three years before his death from other diseases. Because sigmoid colon volvulus often occurs in the elderly and in complex patients, surgery is often associated with high mortality rates. At the same time, conventional endoscopic treatments are associated with high recurrence rates. Our case suggests that PEC is an effective treatment for recurrent sigmoid colon volvulus in high-risk patients.

We describe a case of hepatic biloma that was treated with the rendezvous method. The case was a 49-year-old female. Hepatic resection was performed for metastatic liver cancer. Five months later, the patient presented to our hospital with a fever. Computed tomography revealed that bile was leaking and that the posterior branch of the intrahepatic bile duct had ruptured at the point where it joins the common bile duct.

Drainage by an endoscopic procedure was not possible. Therefore, percutaneous transhepatic biliary drainage (PTBD) was performed. A guidewire was advanced into the site of the biliary leakage via the PTBD tube. Then, a free end of the guidewire was grasped with a trans-papillary delivered forceps at the leakage site and passed through the working channel of the duodenoscope. Eventually, a catheter could be successfully inserted over the guidewire into the posterior branch through the papilla.

Clostridium difficile infection (CDI), which typically occurs after the administration of antibiotics, can become severe and result in death of elderly patients and immunocompromised patients. Fecal microbiota transplantation (FMT) is attracting attention because of its high efficacy against CDI, especially refractory and recurrent CDI. FMT is a treatment in which healthy donor stool is administered directly to the digestive tract of patients using endoscopy or nasogastric tubes. Recently, oral administration of encapsulated feces has also been reported. Moreover, there are few serious adverse events, and the efficacy rate against CDI reaches about 90％. On the other hand, the effectiveness of FMT has not yet been established for inflammatory bowel diseases and other disorders in which the alteration in gut microbiota has been reported to be involved in their pathogenesis.

The “Gastrointestinal Endoscopic Clinical Guidelines for Antithrombotic Drug Users,” published by the Japan Gastroenterological Endoscopy Society in 2012, considers the risk of thromboembolic complications accompanying the discontinuation of antithrombotic drugs, as well as the risk of bleeding accompanying endoscopic treatment. However, future prospective studies are necessary because each situation including the antithrombotic drug that the patient is taking, type of endoscopic treatment and the patientʼs status, has a low evidence level. Because of the variable bleeding risk of each situation, it is difficult to determine whether to manage them similarly. To confirm the present condition of digestive endoscopy in antithrombotic drug users, here we investigated the status of acceptance of the current guidelines and the present situation of antithrombotic drug withdrawal during endoscopic biopsy or treatment at hospitals and clinics in the Hokuriku region. We sent a questionnaire to board-certified endoscopist members of the Japan Gastroenterological Endoscopy Society about the current situation of digestive endoscopy in antithrombotic drug users at their institutions. Endoscopists at 78 institutions (48 hospitals, 30 clinics) answered the questionnaire; overall, 79.2% of hospitals and 48.3% of clinics followed the guidelines (p=0.007). Among the endoscopists who performed endoscopic biopsies on antithrombotic drug users, 71.4% reported performing endoscopic biopsies on patients who continued taking aspirin; 62.3% on patients who continued taking thienopyridine derivatives; 54.5% on patients who continued taking warfarin; 57.1% on patients who continued taking direct oral anticoagulants (DOAC); and 14.3-20.8% on patients who continued taking various combinations of these drugs. The rate of endoscopists performing endoscopic treatment in patients with both a high bleeding risk and high thromboembolism risk due to continuation of antithrombotic drug use during endoscopy varied widely depending on the type of endoscopic treatment: of the respondents, 17.5-78.4% reported

performing endoscopic treatment on patients who continued taking aspirin; 0.0-78.4% on patients who continued taking thienopyridine derivatives; 0.0-64.9% on patients who continued taking warfarin; and 0.0-64.9% on patients who continued taking DOAC. In conclusion, endoscopists in clinics were more cautious than those in hospitals with regard to performing endoscopies in antithrombotic drug users. Among the endoscopic treatments with high bleeding risk, a large gap exists in the decision of antithrombotic drug withdrawal. It is necessary to accumulate further evidence so that all endoscopists can be convinced of the safety of endoscopy in patients who continue to take antithrombotic drugs during endoscopic procedures.

Background and Aim: Although several drugs may induce small-bowel mucosal injuries, it is unclear whether these injuries contribute to overt small-bowel bleeding. This study was designed to evaluate the associations between drug use and small-bowel mucosal injury and between these mucosal injuries and overt bleeding in a disease-relevant population.

Methods: We retrospectively studied patients with suspected small-bowel diseases who underwent capsule endoscopy between 2010 and 2013. Drug exposure, Charlson Comorbidity Index, smoking, and alcohol consumption were assessed before capsule endoscopy. Adjusted odds ratios (AOR) and confidence intervals (CI) were estimated for small-bowel mucosal injury and small-bowel overt bleeding.

Results: In total, 850 patients were analyzed during the study period. Median age was 64 years, and 544 patients (64.0%) were men. Among the patients with small-bowel mucosal injury (n = 60) and without mucosal injury (n = 705), use of nonsteroidal anti-inflammatory drugs (NSAIDs) (AOR 1.8, 95% CI 1.01-3.31) was significantly associated with an increased risk of small-bowel mucosal injury compared with non-use. Patients with small-bowel mucosal injury with overt bleeding (n = 85) and without overt bleeding (n = 60) were compared, and no significant difference between the groups in the usage rates for NSAIDs, thienopyridine, other antiplatelets, anticoagulants, acetaminophen, tramadol hydrochloride, or steroids was revealed, even after adjusting for confounders.

Conclusion: Although the use of NSAIDs was significantly associated with an increased risk of small-bowel mucosal injury, no significant associations were observed between the use of such drugs and small-bowel overt bleeding.