Inflammatory bowel disease (IBD), encompassing Crohn’s disease (CD) and ulcerative colitis, is a chronic condition marked by immune dysregulation, genetic predisposition, and metabolic disturbances. Emerging evidence highlights the role of lipid metabolism and peroxisome proliferator-activated receptor (PPAR) signaling in modulating immune responses in IBD. PPAR-γ and PPAR-α regulate macrophage polarization, T-cell differentiation, and epithelial barrier integrity, influencing disease severity and progression. Alterations in PPAR activity contribute to metabolic stress and inflammation, linking IBD pathophysiology to immunometabolism. Studies suggest that targeting PPARs may mitigate inflammation through modulation of cytokine production, immune cell function, and gut microbiota interactions. In this review, we focus specifically on CD and explore how PPAR signaling intersects with mesenteric adipose tissue dysfunction and microbial dysbiosis, 2 hallmark features of CD. PPAR agonists, already used in metabolic-inflammatory diseases such as metabolic-associated liver disease, have demonstrated antiinflammatory effects in experimental colitis models. Translating these findings into clinical applications could offer novel treatment strategies for CD. Future research should focus on clinical trials, genetic studies, and microbiota-targeted approaches to elucidate PPAR-driven mechanisms in CD pathogenesis. Understanding the interplay between PPARs, lipid metabolism, and immune responses may lead to innovative therapeutic strategies, improving disease management and patient outcomes.

Background/Aims: Cold snare polypectomy (CSP) is recommended for colorectal polyps <10 mm; however, the impact of snare size on clinical outcomes remains unclear. This study evaluated the efficacy and safety of 10-mm and 15-mm snares for CSP of small colorectal polyps. Methods: In this prospective multicenter study, patients with 4–10 mm non-pedunculated polyps underwent CSP with either a 10-mm or 15-mm snare. Both snares had identical wire thickness and hexagonal loop design. The primary outcome was histological complete resection rate (CRR). Secondary outcomes included adverse events and technical parameters. Results: In total, 182 patients were enrolled (10-mm group: n = 92; 15-mm group: n = 90). Baseline characteristics, including age, sex, polyp size, morphology, location, and pathology, were comparable between groups. Histological CRRs were 90.2% in the 10-mm group and 91.1% in the 15-mm group (P= 0.483). No significant differences were observed in the presence of submucosal tissue within specimens (P= 0.523), iatrogenic ulcer size (P= 0.532), hematoma occurrence (P= 0.391), or intraprocedural bleeding requiring hemostasis (6.5% vs. 5.6%; P= 0.974). No cases of delayed bleeding or perforation were reported. Logistic regression analysis identified iatrogenic ulcer size > 8 mm as an independent predictor of complete resection (odds ratio, 3.89; 95% confidence interval, 1.15–13.21; P= 0.029); snare size was not significantly associated with CRR (P= 0.519). Conclusions CSP using either a 10-mm or a 15-mm snare for 4–10 mm non-pedunculated colorectal polyps showed no significant difference in complete resection or safety outcomes within this size range. (Clinical Research Information Service [CRIS], KCT0005031)

Janus kinase (JAK) inhibitors are an important treatment option for ulcerative colitis, providing rapid onset of action, oral administration, and efficacy even after biologic failure. The 3 approved agents—tofacitinib, filgotinib, and upadacitinib—differ in JAK isoform selectivity, leading to clinically meaningful differences in efficacy and safety. Evidence from network meta-analyses, clinical trials, and real-world studies consistently shows that upadacitinib provides the highest efficacy for induction and maintenance of remission, whereas filgotinib demonstrates the most favorable safety profile. The strong efficacy of upadacitinib and tofacitinib is particularly relevant in patients with severe disease, including acute severe ulcerative colitis, and upadacitinib maintains high efficacy regardless of prior advanced therapy exposure. JAK inhibitors also benefit extraintestinal manifestations. Although risks such as herpes zoster, serious infection, thromboembolism, and major cardiovascular events differ among agents, long-term data suggest generally acceptable safety when used appropriately. Intraclass JAK-to-JAK cycling is feasible, with about half of patients achieving steroid-free clinical remission in retrospective cohorts. Based on mechanistic, clinical, and real-world evidence, filgotinib may be a first-line option for patients with lower disease activity or when safety is a priority, whereas upadacitinib or tofacitinib may be preferred in higher disease activity. Strategically selecting agents may improve durability and outcomes.

Background/Aims: Both endoscopic resection (ER) and transanal surgery (TAS) are minimally invasive treatment options that allow organ preservation in early rectal tumors. We conducted a meta-analysis to compare treatment outcomes between the 2 treatments. Methods: We searched all relevant studies published until January 2024 that examined the comparative outcomes between ER and TAS for rectal tumors, including adenoma, adenocarcinoma, and neuroendocrine tumor (NET). TAS included transanal excision, transanal endoscopic microsurgery, and transanal minimally invasive surgery. Results: Seventeen studies with a total of 1,569 patients were included in this meta-analysis. For adenoma/adenocarcinoma, the R0 resection rate did not differ between ER and TAS (risk ratio [RR], 0.99; 95% confidence interval [CI], 0.94–1.03). For NET, the R0 resection rate was lower in the ER group than in the TAS group (RR, 0.76; 95% CI, 0.68–0.84) and the procedure time for ER was shorter than that for TAS. For both adenoma/adenocarcinoma and NET, ER and TAS did not differ in terms of complication rates, additional surgery, and recurrence. Conclusions ER and TAS showed similar treatment outcomes for adenoma/adenocarcinoma. Considering that TAS typically incurs higher costs than ER, ER may be favored in the treatment of rectal adenoma/adenocarcinoma. For rectal NET, TAS showed a superior R0 resection rate than ER. However, given that TAS requires a long procedure time, expensive equipment, and complex manipulations, TAS may be considered selectively for large NETs with suspected deep tumorous infiltration.

Crohn’s disease is a chronic inflammatory disease of the digestive tract with extraintestinal manifestations, which include skin conditions, arthritis, ocular inflammation, and several autoimmune conditions. Dermatologic manifestations in Crohn’s disease complicate the treatment course and prognosis and should be addressed promptly. Here, we report a 20-year-old male with a history of Crohn’s disease, presenting with palpable purpura, consistent with Henoch-Schönlein purpura, upon administration of ustekinumab. The immunoglobulin A vasculitis was treated with prednisone and the discontinuation of ustekinumab. Due to the increased usage of biological agents in inflammatory bowel diseases, associations between biologics and vasculitides should be further studied in Crohn’s disease patients for alternative treatment strategies and to understand potential adverse effects caused by biologics in Crohn’s disease.