Seung Bum Lee

Iatrogenic colonic perforation is a rare but serious complication of colonoscopy, particularly during therapeutic procedures. Prompt recognition and individualized management are essential to prevent adverse outcomes. This review summarizes current treatment strategies based on major international guidelines. Endoscopic closure is recommended for selected cases involving minor defects, early detection, and adequate bowel preparation. Techniques such as clipping, endoloop application, and suturing have demonstrated favorable success rates. Surgical intervention is crucial for larger, delayed, or complicated perforations, particularly those associated with significant contamination or clinical deterioration. Recognizing risk factors such as age, diverticulosis, and inadequate bowel preparation can help prevent this complication.

Park GM, et al. J Korean Med Sci. 2026 Apr;41(16):e127. https://doi.org/10.3346/jkms.2026.41.e127

Background/Aims: Assessing the risk of colorectal cancer (CRC) after kidney transplantation (KT) in patients with endstage renal disease (ESRD) receiving dialysis is crucial to determine KT’s risks and benefits. In Korea, the study results remain unclear. Therefore, using a nationwide health screening and claims database, this longitudinal study aimed to investigate CRC risk in KT recipients versus patients with ESRD receiving hemodialysis.Methods: This research recruited 65,154 participants (60,202 on dialysis vs. 4,955 with KT) from the database of the Korean National Health Insurance Service, which provides mandatory health insurance to all Korean citizens. These participants were followed up from the baseline to CRC development, loss of follow-up, or study completion. The landmark method was used to effectively control the immortal time bias.Results: During the follow-up period, the incidence of CRC was 2.9 per 1,000 person-years in the dialysis group and 1.2 per 1,000 person-years in the KT group (p < 0.001). The mean time for CRC development in the dialysis and KT groups was 4.5 and 4.8 years, respectively. Compared with dialysis patients, the KT group obtained an adjusted hazard ratio of 0.54 for CRC (95% confidence interval, 0.42–0.71; p < 0.001). Landmark analysis showed that the 15-year cumulative CRC incidence was significantly higher in the dialysis group than in the KT group after landmark time points of 3 and 5 years (p < 0.0001).Conclusions: The risk of CRC after KT remained significantly lower than that of patients undergoing dialysis, even after landmark analysis.

Seung Bum Lee. Journal of Digestive Cancer Research 2025;13:112-9. https://doi.org/10.52927/jdcr.2025.13.2.112

Acute graft-versus-host disease (GVHD) is a major complication following allogeneic hematopoietic stem cell transplantation. Steroid-refractory cases have poor outcomes, so an accurate diagnosis, particularly differentiation from cytomegalovirus colitis, is critical. Ruxolitinib is the standard second-line therapy, while Vedolizumab has shown potential in gut-specific modulation. Recent studies have reported that reduced microbiome diversity and the loss of short-chain fatty acid-producing bacteria are linked to acute GVHD severity and mortality. Fecal microbiota transplantation may offer benefit in selected steroid-refractory cases, but the evidence remains limited and variable. Gastroenterologists play an essential role in diagnosis and microbiome-guided care. A personalized approach incorporating microbial biomarkers may improve the future outcomes.

Background/Objectives: The clinical characteristics of colorectal mucosa-associated lymphoid tissue (MALT) lymphoma remain poorly defined, and there is no standardized treatment for the disease. Therefore, we investigated the clinical characteristics of colorectal MALT lymphoma and its prognosis based on different treatment modalities. Methods: A retrospective analysis was performed on patients diagnosed with colorectal MALT lymphoma from 2003 to 2021 across six hospitals in Korea’s Busan–Ulsan–Gyeongnam area. Macroscopic findings classified all cases into polyposis type, mass-forming type, subepithelial lesion type, and inflammatory type. Results: Fifty-one patients were enrolled. The median age was 59 years, and 27 patients (52.9%) were male. Five patients (9.8%) were stage IV at initial diagnosis. As for the endoscopic type, the polyposis type was the most common (39.2%). There was no statistically significant difference in disease progression according to the endoscopic type (p = 0.813). Three cases of disease progression were confirmed in stage I after treatment, and one of them died due to disease progression. No disease progression was identified in other stages. According to the treatment modality, disease progression was identified in 1 of 16 patients who underwent endoscopic resection and 2 of 16 patients who underwent chemotherapy. There was no disease progression in the observation group. However, there was no statistically significant difference in disease progression according to treatment modality (p = 0.889). Conclusions: Colorectal MALT lymphoma showed good prognosis regardless of the initial stage, endoscopic type, or treatment modality.

Background: Few studies have compared the efficacy and safety of second-line biological therapies in ulcerative colitis (UC) patients with prior exposure to anti-tumor necrosis factor (TNF) therapy. We aim to compare the efficacy and safety between ustekinumab, vedolizumab, and tofacitinib, a current option as second-line biological therapy with different mechanisms in those patients. Methods: This retrospective multi-center study was conducted across five institutions from 2011 to 2022. We enrolled patients with moderate to severe UC who failed anti-TNF therapy and subsequently received ustekinumab, vedolizumab, or tofacitinib as second-line biological therapy. The outcomes were analyzed for clinical response/remission and endoscopic improvement/remission rates after induction therapy, drug persistency, and adverse events. Results: A total of 70 UC patients were included and grouped into ustekinumab (11 patients), vedolizumab (40 patients), and tofacitinib (19 patients) treatments. The clinical response/remission rates after induction therapy were similar between ustekinumab (90.9/81.8%), vedolizumab (92.5/65.0%), and tofacitinib (94.7/73.7%). There were no significant differences in the endoscopic improvement/remission rates between the three groups: 90.9/18.2% for ustekinumab, 72.5/12.5% for vedolizumab, and 84.2/26.3% for tofacitinib. Drug persistence was similar across the three agents (p = 0.130). Three patients of the tofacitinib group experienced adverse events (herpes zoster and hypertriglyceridemia). Conclusions: Based on real-world data, second-line biological therapy with ustekinumab, vedolizumab, and tofacitinib showed comparable efficacy in patients with moderate to severe UC with prior exposure to anti-TNF therapy.

Predicting treatment response in Crohn’s disease (CD) patients initiating biological therapy is crucial. The first step involves considering symptom control and normalization of C-reactive protein (CRP). However, data on the actual rates of achieving CRP normalization and the appropriate timeframe are lacking. Therefore, we aim to investigate the rate of attaining CRP normalization and identify its optimal timeframe in CD patients initiating biological therapy. In this retrospective multi-center study, we analyzed moderate to severe CD patients initiating biological therapy from January 2012 to July 2023. The primary outcome was the rate and timeframe for achieving CRP normalization. Secondary outcomes included clinical outcomes in patients who achieved CRP normalization and factors associated with early CRP normalization. Of 183 patients, 123 (67.2%) achieved CRP normalization, with a median duration of 3.8 months (interquartile range 1.4 to 7.4 months). The duration and value difference for CRP normalization between anti-tumor necrosis factor agents, ustekinumab, and vedolizumab were statistically insignificant. Cumulative rates of CD-related hospitalization, intestinal resection, and drug discontinuation over 8 years were 11.4%, 2.4%, and 12.2%, respectively. The duration of CRP normalization correlates with drug discontinuation (area under the curve: 0.64). Treatment with 5-aminosalicylic acid (HR 2.77; 95% confidence interval [CI] 1.26–6.11) and high albumin level (HR 1.64, 95% CI 1.04–2.61) favored early CRP normalization, whereas structuring behavior less likely than inflammatory behavior (HR 0.43, 95% CI 0.19–0.96). We have provided the actual rate of achieving CRP normalization and its appropriate timeframe as an initial target in CD treatment.

Background/Aims: The achievement of endoscopic remission is an important therapeutic goal in the treatment of inflammatory bowel diseases (IBD). We aimed to evaluate the role of fecal calprotectin (FCP) and ischemia-modified albumin (IMA) as biomarkers for evaluating IBD disease activity.Methods: A total of 48 patients with IBD (20 with ulcerative colitis and 28 with Crohn’s disease) were included in this study. FCP and serum C-reactive protein levels, erythrocyte sedimentation rate, and IMA were measured in patients with IBD and compared with endoscopic findings.Results: Elevated FCP and serum IMA levels were significantly associated with endoscopic non-mucosal healing. The correlation between FCP and IMA was not significant. Analysis of the receiver operating characteristic curve showed that both FCP and IMA had diagnostic value in predicting non-mucosal healing. When the Ln(FCP)+IMA/10 value was calculated using both factors, the predictive value for non-mucosal healing increased; however, no significant difference was observed.Conclusions: IMA could be a candidate serum biomarker for predicting endoscopic mucosal healing in IBD.