Accurate diagnosis of Helicobacter pylori (H. pylori) infection is mandatory for the effective management of many gastroduodenal diseases. Currently, various diagnostic methods are available for detecting these infections, and the choice of method should take into account the clinical condition, accessibility, advantage, disadvantage, as well as cost-effectiveness. The diagnostic methods are divided into invasive (endoscopic-based) and non-invasive methods. Non-invasive methods included urea breath test, stool antigen test, serology, and molecular methods. Invasive methods included endoscopic imaging, rapid urease test, histology, culture, and molecular methods. In this article, we provide a review of the currently available options and recent advances of various diagnostic methods.

While the prevalence of Helicobacter pylori (H. pylori) infection is decreasing in Korea, the incidence of gastric cancer remains high, emphasizing the importance of H. pylori eradication. A new treatment strategy is needed as the eradication rate with standard triple therapy, which is currently the standard first-line regimen for H. pylori infection, has decreased below the optimum level. The major cause of eradication failure is increased antibiotic resistance. Sequential, concurrent, and hybrid therapies that include clarithromycin produce higher eradication rates than conventional standard triple therapy. However, the effectiveness of these treatments is limited in regions where the resistance rate to various antibiotics is high. Bismuth quadruple therapy is another alternative therapy, but again the eradication rate is not sufficiently high. Tailored therapy based on individual characteristics, including antibiotic susceptibility, may be ideal, but there are several limitations for clinical application and further research is needed. New potassium-competitive acid blocker-based therapies could emerge as effective alternatives in the near future. A consensus is needed to establish a strategy for applying new eradication therapies in Korea.

Gastric cancer is the most common cancer in Korea and the fifth most common cancer globally. Helicobacter pylori (H. pylori) infection is considered the main etiologic agent for gastric cancer development. Most regional guidelines for H. pylori treatment recommend treating the organism to prevent gastric cancer in the high-risk group. However, evidence that such a strategy can also be applied to the general population, especially in terms of the preventive effect and safety, has not been adequately presented yet. Although a meta-analysis in the general population suggested effectiveness in decreasing gastric cancer incidence, individual studies should be critically reviewed to evaluate the soundness of the evidence. Recently published, long-term, Korean studies on metachronous gastric cancer prevention ended the controversies from previous short-term studies and confirmed the effectiveness. Currently, further prospective, large, randomized studies are ongoing in the general population and will provide more definitive, high-level evidence on this gastric cancer prevention strategy in the next decade.

This guidance is an updated version of the irritable bowel syndrome (IBS) guidelines based on evidence-based medicine. IBS is a common chronic gastrointestinal syndrome that occurs in approximately 10% of the population and causes chronic abdominal pain as well as bowel habit changes, such as stool frequency or consistency. The final diagnosis of IBS is based on the exclusion of organic diseases that would explain the symptoms and the absence of endoscopic abnormalities. IBS can reduce the quality of life and cause a major disease burden, such as repeated examinations and continuous drug use, by mistaking organic diseases including malignancy. The major changes are as follows: 1) when to perform a colonoscopy under the impression of IBS; 2) effect of a low-fermentable oligosaccharides, disaccharides, monosaccharides, and polyol diet; 3) impact of probiotics in IBS; and 4) role of antibiotics in IBS. The Korean Society of Neurogastroenterology and Motility recently updated these guidelines to support physicians for qualified medical services and reduce the socioeconomic burden of IBS.

Esophageal basaloid squamous carcinoma (BSC) is a rare, aggressive variant of squamous cell carcinoma. BSC is usually diagnosed in advanced stage and its prognosis is relatively poor. A 59-year-old male with subepithelial lesion of the esophagus that was incidentally discovered during health promotion examination was referred to our hospital. Esophagogastroduodenoscopy showed a 10-mm bulging mucosa with an intact surface at 34 cm from incisor teeth. Endoscopic ultrasonography revealed a smooth margined homogenous hypoechoic lesion, measuring 11.3×3.9 mm with a submucosal layer of origin. The patient underwent endoscopic mucosal resection of the subepithelial lesion. Pathologic examination of the resected specimen revealed BSC with involvement of vertical margin by tumor. The patient then underwent radiotherapy, and is doing well without recurrence for 35 months. We report a case of esophageal BSC confined to submucosal layer successfully treated with endoscopic resection followed by radiation.

Surgery has been the standard treatment for perforated duodenal ulcers, with mostly good results. However, the resolution of postoperative leakage after primary repair of perforated duodenal ulcer remains challenging. There are several choices for re-operation required in persistent leakage from perforated duodenal ulcers. However, many of these choices are complicated surgical procedures requiring prolonged general anesthesia that may increase the chances of morbidity and mortality. Several recent reports have demonstrated postoperative leakage after primary repair of a perforated duodenal ulcer treated with endoscopic insertion using a covered self-expandable metallic stent, with good clinical results. We report a case with postoperative leakage after primary repair of a perforated duodenal ulcer treated using a covered self-expandable metallic stent.