Chronic constipation is one of the most common digestive diseases encountered in clinical practice. Constipation manifests as a variety of symptoms, such as infrequent bowel movements, hard stools, feeling of incomplete evacuation, straining at defecation, a sense of anorectal blockage during defecation, and use of digital maneuvers to assist defecation. During the diagnosis of chronic constipation, the Bristol Stool Form Scale, colonoscopy, and a digital rectal examination are useful for objective symptom evaluation and differential diagnosis of secondary constipation. Physiological tests for functional constipation have complementary roles and are recommended for patients who have failed to respond to treatment with available laxatives and those who are strongly suspected of having a defecatory disorder. As new evidence on the diagnosis and management of functional constipation emerged, the need to revise the previous guideline was suggested. Therefore, these evidence-based guidelines have proposed recommendations developed using a systematic review and meta-analysis of the treatment options available for functional constipation. The benefits and cautions of new pharmacological agents (such as lubiprostone and linaclotide) and conventional laxatives have been described through a meta-analysis. The guidelines consist of 34 recommendations, including 3 concerning the definition and epidemiology of functional constipation, 9 regarding diagnoses, and 22 regarding managements. Clinicians (including primary physicians, general health professionals, medical students, residents, and other healthcare professionals) and patients can refer to these guidelines to make informed decisions regarding the management of functional constipation.

Objectives: Gastrointestinal cytomegalovirus (CMV) disease is a major contributor to mortality in immunocompromised patients. Few studies have discussed upper gastrointestinal CMV (UGICMV) disease in immunocompetent patients. We compared the clinical outcomes of UGI-CMV between immunocompromised and immunocompetent patients. Methods: This retrospective study included patients with UGI-CMV disease from five tertiary hospitals across Korea (2010– 2022). Patients’ clinical data and outcomes were recorded. Results: UGI-CMV was diagnosed in 54 patients; 27 (50.0%) had esophageal, 24 (44.4%) had gastric, and 3 patients (5.6%) had duodenal involvement. Patients’ median age was 64 years (interquartile range 53–75 years), and the most common comorbidities included hypertension (57.4%) and diabetes (38.9%). The predominant symptom was abdominal pain (46.3%), and the most common endoscopic finding was ulcers (70.4%). Antiviral treatment was administered to 31 patients, and 23 patients underwent observation without treatment. We investigated 32 immunocompromised (59.3%) and 22 immunocompetent (40.7%) patients and observed no intergroup differences in comorbidities and in laboratory and endoscopic findings. Immunocompromised patients had longer length of hospitalization (median 46.2 days vs. 20.0 days, p=0.001). However, treatment outcomes, including the need for intensive care unit admission and mortality did not significantly differ. The overall mortality rate was 13.0%; one patient from the immunocompromised group died of UGI-CMV disease. The treatment success rate was higher in immunocompromised patients who received antiviral therapy (p=0.011). Conclusions UGI-CMV disease is not uncommon in immunocompetent patients, although symptoms are milder than those in immunocompromised patients. Our findings emphasize the importance of clinical vigilance for accurate diagnosis of CMV infection, particularly in susceptible symptomatic patients and highlight the need for active antiviral treatment for management of immunocompromised patients.

Gastritis is common worldwide. The combination of Helicobacter pylori (H. pylori) infection with background gastritis, including atrophic gastritis or intestinal metaplasia is implicated as an important etiopathogenetic contributor to gastric cancer. Since the gastritis classification proposed by Schindler, research has focused on classification of gastritis for accurate diagnosis and prediction of prognosis. Advances in endoscopic technology have enabled more accurate visualization of the gastric mucosa and ‘targeted’ biopsies with the emergence of newer classifications based on visual findings (Kimura-Takemoto classification) and more specific histopathological findings using targeted biopsies (Whitehead classification). Following the discovery of H. pylori, it is mandatory to consider its role as an important contributor to gastritis. Therefore, it was necessary to redefine the classification of gastritis and arrive at a consensus, which led to the establishment of an international consensus classification, referred to as the Sydney system. However, the Sydney system alone cannot predict the gastric cancer risk, and scoring systems such as the Operative Link for Gastritis Assessment and the Operative Link on Gastritis Assessment based on Intestinal Metaplasia were proposed. These systems are based on histopathological findings observed in endoscopic biopsy specimens. However, availability of high-definition images following technological advances has facilitated the emergence of a visual classification, the Kyoto classification. In contrast to the Sydney system, the Kyoto classification is based exclusively on interpretation of visual findings and focuses on detection of H. pylori infection and gastric cancer prediction. In this review, we summarize the history and background of the various classifications of gastritis.

Background: Due to impaired cell-mediated immunity, solid organ transplantation (SOT) recipients are at increased risk of developing nontuberculous mycobacterial pulmonary disease (NTM-PD). However, the clinical course of NTM-PD in SOT patients and the impact of SOT on the prognosis of NTM-PD remain unclear. Methods: We analyzed patients who developed NTM-PD after receiving SOT between January 2001 and December 2020, at a tertiary referral hospital in South Korea. Baseline characteristics, clinical course, and prognosis were evaluated. Propensity score-matched analysis was performed to assess the impact of SOT on long-term survival in patients with NTM-PD. Results: Among 4,685 SOT recipients over 20 years, 12 patients (median age, 64 years;interquartile range [IQR], 59–67 years; men, 66.7%) developed NTM-PD. Seven (58.3%) and five (41.7%) patients underwent kidney and liver transplantation, respectively, before the diagnosis of NTM-PD. The incidence of NTM-PD was 35.6 cases per 100,000 person-years among kidney transplant recipients and 28.7 cases per 100,000 person-years among liver transplant recipients. The median time between transplantation and the diagnosis of NTMPD was 3.3 (IQR, 1.5–10.8) years. The most common mycobacterial species was Mycobacterium avium (50.0%). Antibiotic treatment was initiated in five (41.7%) patients, and two patients (40.0%) achieved microbiological cure. Two patients died during a median follow-up of 4.2 (IQR, 2.3–8.8) years and NTM-PD was assumed to be the cause of death in one patient. When matched to patients without a history of SOT, patients with a history of SOT did not show worse survival (P value for log-rank test = 0.62). Conclusion The clinical course of NTM-PD in SOT recipients was comparable to that of patients without SOT, and SOT did not increase the risk of all-cause mortality in patients with NTM-PD.

Background/Aims: Fecal microbiota transplantation (FMT) represents a treatment option for recurrent Clostridioides difficile infection (CDI). Recently, FMT has been investigated in various clinical settings other than CDI. This study examined Korean physicians’ recognition of FMT and their attitudes toward this procedure Methods: An online questionnaire included questions on indications for FMT, the FMT process, physicians’ attitudes toward FMT for the treatment of CDI and non-CDI diseases, and possible concerns. Results: Finally, 107 physicians responded to this survey: 66 (61.7%) had experience of performing FMT, and 86 (80.4%) replied that they were willing to perform FMT for CDI. Two-thirds of physicians (63.6%, n = 68) would perform FMT for recurrent CDI on patients who had at least three recurrences. The most common obstacle to performing FMT for the treatment of CDI was the lack of regulations or guidelines (55.1%, n = 59). Seventy-seven (72.0%) physicians would consider FMT for non- CDI diseases when conventional treatment had failed. The most common obstacle for FMT for the treatment of non-CDI diseases was low treatment efficacy (57.0%, n = 61). Conclusions Two-thirds of Korean physicians had experience of performing FMT, and many performed FMT for recurrent CDI. The results of this study will prove useful to researchers and practitioners in FMT in Korea.

Fecal microbiota transplantation (FMT) is a highly efficacious and safe modality for the treatment of recurrent or refractory Clostridioides difficile infection (CDI), with overall success rates of 90%. Thus, FMT has been widely used for 10 years. The incidence and clinical characteristics of CDI, the main indication for FMT, differ between countries. To date, several guidelines have been published. However, most of them were published in Western countries and therefore cannot represent the Korean national healthcare systems. One of the barriers to performing FMT is a lack of national guidelines. Accordingly, multidisciplinary experts in this field have developed practical guidelines for FMT. The purpose of these guidelines is to aid physicians performing FMT, which can be adapted to treat CDI and other conditions.

Background/Aims: Besifovir dipivoxil maleate (BSV), an acyclic nucleotide phosphonate, shows potent antiviral activity against hepatitis B virus. Our previous 48-week trial revealed that BSV has comparable antiviral efficacy to tenofovir disoproxil fumarate (TDF) and better safety profiles in terms of improved renal and bone safety. This extension study evaluated the prolonged efficacy and safety of BSV in treatment-naive chronic hepatitis B patients. Methods: Patients continued to participate in an open-label BSV study after an initial 48-week double-blind comparison of BSV and TDF treatment. The antiviral efficacy and drug safety was evaluated up to 192 weeks in two groups: patients continuing BSV treatment (BSV-BSV) and patients switching from TDF to BSV after 48 weeks (TDF-BSV). Results: Among 197 patients receiving randomized treatments, 170 (86%) entered the open-label phase and 152 (77%) entered the 192-week extension study. Virological response rates over 192 weeks were 92.50% and 93.06% in the BSV-BSV and TDF-BSV groups, respectively (P=0.90). Hepatitis B envelop antigen seroconversion and alanine aminotransferase normalization rates were similar between the groups (P=0.75 and P=0.36, respectively). There were no drug-resistant mutations to BSV. Bone mineral density and renal function were well preserved in the BSV-BSV group, whereas these initially worsened then recovered after switching therapy in the TDF-BSV group. Conclusions BSV maintained potent antiviral efficacy after 192 weeks and showed no evidence of drug resistance. BSV was safe, well tolerated, and effective in patients who switched from TDF to BSV. Trial Registration Number: NCT01937806 (date: 10 Sep 2013).

Background/Aims: Besifovir dipivoxil maleate (BSV), an acyclic nucleotide phosphonate, shows potent antiviral activity against hepatitis B virus. Our previous 48-week trial revealed that BSV has comparable antiviral efficacy to tenofovir disoproxil fumarate (TDF) and better safety profiles in terms of improved renal and bone safety. This extension study evaluated the prolonged efficacy and safety of BSV in treatment-naive chronic hepatitis B patients. Methods: Patients continued to participate in an open-label BSV study after an initial 48-week double-blind comparison of BSV and TDF treatment. The antiviral efficacy and drug safety was evaluated up to 192 weeks in two groups: patients continuing BSV treatment (BSV-BSV) and patients switching from TDF to BSV after 48 weeks (TDF-BSV). Results: Among 197 patients receiving randomized treatments, 170 (86%) entered the open-label phase and 152 (77%) entered the 192-week extension study. Virological response rates over 192 weeks were 92.50% and 93.06% in the BSV-BSV and TDF-BSV groups, respectively (P=0.90). Hepatitis B envelop antigen seroconversion and alanine aminotransferase normalization rates were similar between the groups (P=0.75 and P=0.36, respectively). There were no drug-resistant mutations to BSV. Bone mineral density and renal function were well preserved in the BSV-BSV group, whereas these initially worsened then recovered after switching therapy in the TDF-BSV group. Conclusions BSV maintained potent antiviral efficacy after 192 weeks and showed no evidence of drug resistance. BSV was safe, well tolerated, and effective in patients who switched from TDF to BSV. Trial Registration Number: NCT01937806 (date: 10 Sep 2013).