Background/Aims: We aimed to compare the differences in pediatric Crohn's disease (CD) and ulcerative colitis (UC) at diagnosis in Korea.Methods: This was a multicenter, registry-based, inception cohort study conducted at five centers in Korea between 2013 and 2017. Baseline demographics, clinical characteristics, and results from laboratory, endoscopic, radiologic examinations were compared between pediatric CD and UC patients who were <19 years old at diagnosis. Results:A total 307 patients were included (227 CD [73.9%] and 80 UC [26.1%]). The male to female ratio was 2.49:1 for CD, and 1.49:1 for UC (p=0.019). Median age at diagnosis was 14.4 years (interquartile range, 12.4 to 16.2) for CD, and 14.4 years (interquartile range, 11.7 to 16.5) for UC (p=0.962). Hematochezia was the only dominant symptom in UC patients compared to CD patients (86.2% vs 30.8%, p<0.001). White blood cell counts, platelet counts, erythrocyte sedimentation rate, and C-reactive protein levels were significantly higher, and serum albumin level was significantly lower in CD patients than in UC patient. Anti-Saccharomyces cerevisiae antibody was positive in 44.5% and 16.2% of CD and UC patients, respectively (p<0.001), and antineutrophil cytoplasmic antibody was positive in 15.0% and 58.8% of CD and UC patients, respectively (p<0.001). Terminal ileal involvement was prominent in CD, while rectal involvement was more prominent in UC. Small bowel involvement and perianal perforating diseases were also more prominent in CD.Conclusions: This is the first a multicenter study in Korea to compare the differences between pediatric CD and UC at diagnosis in Korea. A large-scale, national study is expected to better clarify these findings in the future.

Background Studies on how the coronavirus pandemic has affected pediatric inflammatory bowel disease (PIBD) are lacking. We aimed to investigate the trends in epidemiology, characteristics, initial management, and short-term outcomes of PIBD in South Korea over the recent three years including the era of coronavirus disease 2019 (COVID-19). Methods This multicenter study retrospectively investigated temporal trends in the epidemiology of PIBD in Korea. Annual occurrences, disease phenotypes, and initial management at diagnosis were analyzed from January 2018 to June 2021. Results A total of 486 patients from 17 institutions were included in this epidemiological evaluation. Analysis of the occurrence trend confirmed a significant increase in PIBD, regardless of the COVID-19 pandemic. In Crohn’s disease, patients with post-coronavirus outbreaks had significantly higher fecal calprotectin levels than those with previous onset (1,339.4 ± 717.04 vs. 1,595.5 ± 703.94, P = 0.001). Patients with post-coronavirus-onset ulcerative colitis had significantly higher Pediatric Ulcerative Colitis Activity Index scores than those with previous outbreaks (48 ± 17 vs. 36 ± 15, P = 0.004). In the initial treatment of Crohn’s disease, the use of 5-aminosalicylic acid (5-ASA) and steroids significantly decreased ( P = 0.006 and 0.001, respectively), and enteral nutrition and the use of infliximab increased significantly ( P = 0.045 and 0.009, respectively). There was a significant increase in azathioprine use during the initial treatment of ulcerative colitis ( P = 0.020). Conclusion Regardless of the COVID-19 pandemic, the number of patients with PIBD is increasing significantly annually in Korea. The initial management trends for PIBD have also changed. More research is needed to establish appropriate treatment guidelines considering the epidemiological and clinical characteristics of Korean PIBD.

Background Swallowing of foreign bodies (FBs) is the most common indication of therapeutic endoscopy in children. Endoscopic removal may be necessary depending on the type of FB, age of the child, and location of the FB. We attempted to analyze the characteristics of each device used for the endoscopic removal of FBs in children. Methods Medical records of the patient’s age, sex, weight, type, location, size, shape, type of device used for endoscopic removal, and endoscopic time were retrospectively collected. Results A total of 424 FB removal procedures were analyzed. The average age of the patients at the time of FB removal was 4.1 ± 3.7 years. Coins were the most common FBs (192, 45.3%). The most common locations of the FBs were the esophagus (45.7%) and the stomach (48.3%), respectively. For a total of 371 cases, forceps were used in 96 cases (25.9%) for esophageal FBs and in 25 cases for gastric FBs (6.7%), while nets were used in 250 cases (67.4%) for gastric FBs retrieval; the average durations of the procedures were 7.2 ± 7.4 minutes, 8.5 ± 7.2 minutes, and 5.7 ± 7.3 minutes, respectively ( P = 0.003). The procedure time was significantly shorter, in the group of patients with low body weights, when nets were used than when forceps were used to remove gastric FBs ( P = 0.001). Conclusion The endoscopic procedure duration, in low-weight children, was shorter when retrieval nets were used than that with forceps.

Purpose This study evaluated the predictive role of fecal calprotectin (FC) measured at an early stage of treatment for monitoring clinical remission (CR) after six months and endoscopic remission (ER) after one year of treatment in pediatric Crohn’s disease (CD). Methods This retrospective study included 45 patients who simultaneously underwent ileocolonoscopy and FC testing during follow-up. FC levels were measured before and after six weeks of treatment. CR was assessed after six months of treatment using Pediatric Crohn’ s Disease Activity Index and acute-phase reactants. ER was assessed after one year using the Simple Endoscopic Score for Crohn’s Disease. Results Twenty-nine (64.4%) patients used oral prednisolone for remission induction and 16 (35.6%) patients used anti-tumor necrosis factor-alpha. Thirty (66.7%) patients achieved CR, while 24 (53.3%) achieved ER. The FC level measured after six weeks of treatment could predict CR (χ 2 =9.15, p =0.0025) and ER (χ 2 =12.31, p =0.0004). The δFC could predict CR (χ 2 =7.91, p =0.0049), but not ER (χ 2 =1.85, p =0.1738). With a threshold of ≤950.4 µg/g, FC at week six could predict CR with 76.7% sensitivity and 73.3% specificity. The area under the curve (AUC) was 0.769 (standard error 0.0773, p =0.0005). The same threshold predicted ER with 87.5% sensitivity and 71.4% specificity. The AUC was 0.774 (standard error 0.074, p =0.0002). Conclusion FC assay at an early stage of treatment can be used as a surrogate marker to predict CR and mucosal healing in pediatric CD.