Role of Cytolethal Distending Toxin in Altered Stool Form and Bowel Phenotypes in a Rat Model of Post-infectious Irritable Bowel Syndrome.

Background/aimsCampylobacter jejuni infection is a leading cause of acute gastroenteritis, which is a trigger for post-infectious irritable bowel syndrome (PI-IBS). Cytolethal distending toxin (CDT) is expressed by enteric pathogens that cause PI-IBS. We used a rat model of PI-IBS to investigate the role of CDT in long-term altered stool form and bowel phenotypes.MethodsAdult Sprague-Dawley rats were gavaged with wildtype C. jejuni (C+), a C. jejunicdtB knockout (CDT-) or saline vehicle (controls). Four months after gavage, stool from 3 consecutive days was assessed for stool form and percent wet weight. Rectal tissue was analyzed for intraepithelial lymphocytes, and small intestinal tissue was stained with anti-c-kit for deep muscular plexus interstitial cells of Cajal (DMP-ICC).ResultsAll 3 groups showed similar colonization and clearance parameters. Average 3-day stool dry weights were similar in all 3 groups, but day-to-day variability in stool form and stool dry weight were significantly different in the C+ group vs both controls (P < 0.01) and the CDT- roup (P < 0.01), but were not different in the CDT- vs controls. Similarly, rectal lymphocytes were significantly higher after C. jejuni (C+) infection vs both controls (P < 0.01) and CDT-exposed rats (P < 0.05). The counts in the latter 2 groups were not significantly different. Finally, c-kit staining revealed that DMP-ICC were reduced only in rats exposed to wildtype C. jejuni.ConclusionsIn this rat model of PI-IBS, CDT appears to play a role in the development of chronic altered bowel patterns, mild chronic rectal inflammation and reduction in DMP-ICC

Comparison of the efficacy and complications of endoscopic incisional therapy and balloon dilatation for benign esophageal strictures

Background Benign esophageal strictures are treated endoscopically, often with balloon dilatation (BD) or bougie dilators. However, recurrent esophageal strictures have been reported after BD, and severe complications sometimes occur. The aim of this study was to compare the efficacy and complications of endoscopic incisional therapy (EIT) and BD for benign esophageal strictures. Methods We retrospectively reviewed patients who underwent BD or EIT as primary treatment for benign esophageal strictures between July 2014 and June 2021. Technical success was defined as restoration of the lumen diameter with <30% residual stenosis. Clinical success was defined as no recurrence of dysphagia within 1 month after BD or EIT and an increase of 1 grade or more on the Functional Oral Intake Scale. Results Thirty patients with benign esophageal stricture were enrolled. There were 16 patients in the BD group and 14 patients in the EIT group. No significant differences in technical and clinical success rates were found between the two groups. Furthermore, no significant differences in the re-stricture rate were observed between the groups. There was one complication in the EIT group and three complications in the BD group. Three patients who underwent BD had re-stricture and underwent EIT thereafter, and we regrouped patients who underwent EIT at least once. The clinical success rate was significantly higher in patients regrouped to the EIT group than in patients who underwent BD only. Conclusions EIT is not inferior to BD as the primary treatment for benign esophageal strictures, especially for recurrent cases

Comparison of sampling methods in assessing the microbiome from patients with ulcerative colitis

Background Dysbiosis of ulcerative colitis (UC) has been frequently investigated using readily accessible stool samples. However, stool samples might insufficiently represent the mucosa-associated microbiome status. We hypothesized that luminal contents including loosely adherent luminal bacteria after bowel preparation may be suitable for diagnosing the dysbiosis of UC. Methods This study included 16 patients with UC (9 men and 7 women, mean age: 52.13 ± 14.09 years) and 15 sex- and age-matched healthy individuals (8 men and 7 women, mean age: 50.93 ± 14.11 years). They donated stool samples before colonoscopy and underwent luminal content aspiration and endoscopic biopsy during the colonoscopy. Then, the composition of each microbiome sample was analyzed by 16S rRNA-based next-generation sequencing. Results The microbiome between stool, luminal contents, and biopsy was significantly different in alpha and beta diversities. However, a correlation existed between stool and luminal contents in the Procrustes test (p = 0.001) and Mantel test (p = 0.0001). The stool microbiome was different between patients with UC and the healthy controls. Conversely, no difference was found in the microbiome of luminal content and biopsy samples between the two subject groups. The microbiome of stool and lavage predicted UC, with AUC values of 0.85 and 0.81, respectively. Conclusion The microbiome of stool, luminal contents, and biopsy was significantly different. However, the microbiome of luminal contents during colonoscopy can predict UC, with AUC values of 0.81. Colonoscopic luminal content aspiration analysis could determine microbiome differences between patients with UC and the healthy control, thereby beneficial in screening dysbiosis via endoscopy. Trial registration: This trial was registered at http://cris.nih.go.kr . Registration No.: KCT0003352), Date: 2018–11-13.This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (No. 2020R1G1A100923411)

Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder. Its diagnosis is based on symptoms, and the Rome IV criteria are recognized as the gold diagnostic standard. The Korean Society of Neurogastroenterology and Motility (KSNM) recently updated their clinical practice guidelines for the treatment of IBS, which were last issued in 2011. In this updated edition, the KSNM defines IBS as a chronic, recurrent symptom complex that includes abdominal pain or discomfort, changes in bowel habits, and bloating for at least 6 months, which is somewhat broader than the previous definition. Four major topics have been changed in the up-dated version in-line with the results of recent studies, that is, colonoscopy; a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols; probiotics; and rifaximin. Herein, we review the 2017 revised edition of the KSNM with respect to recommended clinical practice guidelines for IBS and compare these with other guidelines

Efficacy of Positron Emission Tomography/Computed Tomography in Gastric Mucosa-associated Lymphoid Tissue Lymphoma

Background : /Aims: This study evaluated the diagnostic efficacy of fluorine-18 fluorodeoxyglucose PET/CT (F-18 FDG PET/CT) for patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma and examined the association between FDG avidity and the clinical factors affecting lesions. Methods : : Among the patients diagnosed with gastric MALT lymphoma, 16 who underwent a PET/CT for gastric MALT lymphoma were semi-quantitatively and qualitatively tested for FDG avidity of lesions in the stomach. Retrospectively collected data was analyzed to investigate the clinicoradiological factors and endoscopic findings between the patients with positive F-18 FDG PET/CT scans and those with negative scans. Results : : Eight of the 16 patients showed FDG avidity. When comparing the size of lesions in the stomach, the patients with FDG avidity had significantly larger lesions than those without (28.8 mm vs. 15.0 mm, p=0.03). The FDG-avid group has a significantly higher rate of positive CT scans than the non-avid group (75% vs. 13%, p=0.03). According to the endoscopic finding of the lesions, FDG avidity was pronounced with 75% of the protruding tumors, and 100% of the erosive-ulcerative types, which are a type of depressed tumors. Conclusion : s: When gastric MALT lymphoma is large, when lesions are found using abdominal CT scans, and the macroscopic appearance of a lesion is that of a protruding tumor or erosive-ulcerative type of depressed tumor, there is a high probability that such patients may have a positive F-18 FDG PET/CT scan. (Korean J Gastroenterol 2016;67:183-188

ICC density predicts bacterial overgrowth in a rat model of post-infectious IBS

AIM: To investigate the interstitial cells of Cajal (ICC) number using a new rat model

Duodenal amyloidosis secondary to ulcerative colitis

Amyloidosis is defined as the extracellular deposition of non-branching fibrils composed of a variety of serum-protein precursors. Secondary amyloidosis is associated with several chronic inflammatory conditions, such as rheumatologic or intestinal diseases, familial Mediterranean fever, or chronic infectious diseases, such as tuberculosis. Although the association of amyloidosis with inflammatory bowel disease is known, amyloidosis secondary to ulcerative colitis (UC) is rare. A 36-year-old male patient with a 15-year history of UC presented with nausea, vomiting, and abdominal pain. He had been treated with infliximab for 6 years. At the time of admission, he had been undergoing treatment with mesalazine and adalimumab since the preceding 5 months. Esophagogastroduodenoscopy showed mucosal erythema, edema, and erosions with geographic ulcers at the 2nd and 3rd portions of the duodenum. Duodenal amyloidosis was diagnosed using polarized light microscopy and Congo red stain. Monoclonal gammopathy was not detected in serum and urine tests, while the serum free light chain assay result was not specific. An increase in plasma cells in the bone marrow was not found. Secondary amyloidosis due to UC was suspected. The symptoms were resolved after glucocorticoid therapy