Patients with inflammatory bowel disease (IBD) are at increased risk for developing colorectal cancer (CRC), although the overall incidence of IBD-associated CRC has been diminishing in recent decades in western countries. As demonstrated in previous studies, the risk of CRC in IBD increases with longer duration, extent of colitis, a familial history of CRC, coexistent primary sclerosing cholangitis, and the degree of inflammation. The pathogenesis of CRC in IBD is poorly understood. Similar to sporadic CRC, IBD-associated CRC is a consequence of sequential episodes of genomic alteration. Multiple inter-related pathways, including immune response by mucosal inflammatory mediators, oxidative stress, and intestinal microbiota, are also involved the pathogenesis of IBD-associated CRC. Continuing colonic inflammation appears to be a factor in the development of CRC; therefore, anti-inflammatory agents such as 5-aminosalicylate compounds and immune modulators have been considered as potential chemopreventive agents. Colonoscopic surveillance is widely accepted as being effective in reducing the risk of IBD-associated CRC, although no clear evidence has confirmed that surveillance colonoscopy prolongs survival in patients with extensive colitis. The traditional recommendation has been quadrantic random biopsies throughout the entire colon; however, several guidelines now have endorsed chromoendoscopy with a target biopsy because of increasing diagnostic yields and reduced workloads for endoscopists and pathologists. New technologies such as narrow band imaging, confocal endomicroscopy, and autofluorescence imaging have not yet been confirmed as surveillance strategies in IBD.

The findings showed PEG to be a safe and feasible procedure, but the patient's nutritional and inflammatory status should be considered in predicting the outcomes of PEG placement.

SUMMARY The melanocortin receptor 4 (MC4R) is a well-established mediator of body weight homeostasis. However, the neurotransmitter(s) that mediate MC4R function remain largely unknown and as a result, little is known about the second-order neurons of the MC4R neural pathway. Single minded 1 (Sim1)-expressing brain regions, which include the paraventricular nucleus of hypothalamus (PVH), represent key brain sites that mediate melanocortin action. We conditionally restored MC4R expression in Sim1 neurons in the background of Mc4r-null mice. The restoration dramatically reduced obesity in Mc4r-null mice. The anti-obesity effect was completely reversed by selective disruption of glutamate release from those same Sim1 neurons. The reversal was caused by lower energy expenditure and hyperphagia. Corroboratively, disruption of glutamate release selectively from adult PVH neurons led to rapid obesity development via reduced energy expenditure and hyperphagia. Thus, this study establishes glutamate as the primary neurotransmitter that mediates MC4Rs on Sim1 neurons in body weight regulation.

Background/AimsStudies concerning the efficacy and safety of single-balloon enteroscopy (SBE) compared with that of double-balloon enteroscopy (DBE) often appear to be conflicting. However, previous studies were performed by endoscopists who were less experienced in SBE compared with DBE.MethodsWe performed a retrospective analysis of SBE and DBE data performed by a single enteroscopist, with expertise in SBE, using a prospective balloon-assisted enteroscopy registry from 2013 to 2015. Furthermore, we performed a comprehensive literature search and meta-analysis of available studies, including the current study, to clarify the efficacy and safety of SBE versus DBE.ResultsA total of 65 procedures in 44 patients with SBE and 74 procedures in 69 patients with DBE were analyzed. There were no significant differences in diagnostic yield (61.1% vs 77.3%, respectively, p=0.397), therapeutic yield (39.1% vs 31.8%, respectively, p=0.548), and complication rate (4.4% vs 2.3%, p=1.000). In the meta-analysis, which included four randomized controlled trials and three observational studies, there were no significant differences in the pooled relative risk and odds ratio for diagnostic and therapeutic yield and complications of SBE compared with those of DBE.ConclusionsThe performance of SBE appears to be similar to that of DBE in terms of diagnostic and therapeutic yield and complications.

Measurement of colon transit time is the most basic and primary tool in evaluating disorders of colonic motility. In particular, it is helpful in pathologic diagnosis and for planning management in patients with constipation. Several techniques for measuring colon transit time currently exist. The standard measurement of colon transit time has been performed using radioopaque marker test. The radioopaque marker test is the most widely used method; it is simple to perform as well as being cost effective. But, this technique produces radiation exposure. Radionuclide scintigraphy and wireless motility capsules are other techniques used to measure colon transit time. In radionuclide scintigraphy, the transit of radioisotope is viewed by gamma camera; this approach has an advantage in that it uses minimal radiation and it allows a physiological assessment of gastrointestinal transit. Wireless motility capsules have been validated most recently, but this technique is not useful in Korea. This review presents the techniques used to measure colon transit time and the interpretations provided in different colon transit studies.

There was a constant incidence rate of metachronous recurrence during a 5-year surveillance period and there was extragastric recurrence at least 4 years after ESD of early gastric cancer even for absolute indications. Therefore, annual or biannual surveillance EGD and abdominal CT might be necessary for at least 5 years after curative ESD for early gastric cancers, with absolute as well as expanded indications.

Background and Aims Although recent studies have reported that inflammatory bowel disease (IBD) is associated with the development of neurodegenerative diseases via chronic intestinal inflammation and the gut-brain axis, there is insufficient evidence supporting this notion. The aim of this study was to determine the risk of neurodegenerative diseases including Parkinson’s disease (PD) and Alzheimer’s disease (AD) in patients with IBD. Methods Using the National Health Insurance Service data for the entire Korean population, we identified patients with IBD and controls from 2009 to 2011 and followed them up until 2017. We selected the controls in a 1:4 ratio based on age and sex for comparison with cases. Results Of 24,830 IBD patients and 99,320 non-IBD controls, 98 IBD patients and 256 controls developed PD, while 644 IBD patients and 2,303 controls developed AD. The overall neurodegenerative disease risk was higher in IBD patients [PD: adjusted hazard ratio (HR), 1.56; 95% confidence interval (CI), 1.24-1.97; AD: adjusted HR, 1.14; 95% CI, 1.05-1.25). Younger IBD patients aged 40-65 years had a higher risk of PD compared to controls (adjusted HR, 2.34; 1.63-3.35)]. In contrast, patients aged ≥65 years had an increased risk of AD compared to controls (adjusted HR, 1.14; 1.04-1.25). In a nested case-control study of the IBD cohort, patients aged ≥65 years and the female sex were risk factors for AD, while living in an urban area was protective against AD. Conclusions The risk of neurodegenerative diseases was higher in IBD patients than in the non-IBD population.

In Korean patients with CD, stricturing, penetrating disease behavior, and smoking habits at the time of diagnosis are independent predictors for CD-related surgery. It was also identified that younger age (< 40 years), ileal involvement, and perianal disease at diagnosis are predictive of a need for immunosuppressive or biological agents.