The present study investigated the risk of active tuberculosis in patients with inflammatory bowel disease (IBD) treated with vedolizumab or ustekinumab, in actual clinical settings in a country with an intermediate tuberculosis burden. The medical records of 238 patients with IBD who received vedolizumab or ustekinumab were retrospectively reviewed at a tertiary referral center in South Korea. All patients had ≥ 3 months of follow-up duration and underwent a latent tuberculosis infection screening test before initiation of the administration of these drugs. Of the 238 patients enrolled, 181 had Crohn’s disease, and 57 had ulcerative colitis. During the median 18.7 months of follow-up, active tuberculosis did not develop in any patient treated with vedolizumab or ustekinumab. Therefore, we concluded that the risk of tuberculosis appears to be low in patients with IBD treated with vedolizumab or ustekinumab in South Korea.

BACKGROUND/AIMS: Fructose malabsorption (FM) mimics symptoms of irritable bowel syndrome (IBS), and its prevalence has increased. Diagnosing FM in IBS is challenging because of its overlap with small intestinal bacterial overgrowth (SIBO). We assessed the prevalence of FM by comparing patients with IBS with asymptomatic control individuals after excluding SIBO using the glucose hydrogen breath test (HBT). METHODS: Patients diagnosed with IBS and asymptomatic control individuals were enrolled prospectively. Dietary habits were assessed with the Food Frequency Questionnaire. After excluding SIBO, participants underwent HBTs with both 15 g and 25 g of fructose. RESULTS: Thirty-five patients with IBS and 35 age- and sex-matched asymptomatic control individuals were enrolled. The 15-g fructose HBT yielded positive results in 7 of the 35 (20.0%) patients with IBS and in 2 of 35 (5.7%) controls (P = 0.070). The 25-g fructose HBT was positive in 16 of the 35 (45.7%) patients with IBS and in 8 of the 35 (22.9%) controls (P = 0.040). Analysis of the Food Frequency Questionnaire responses showed no significant differences between the 2 groups in dietary intake, although patients with IBS showed a significantly higher mean fiber intake than controls (21.24 ± 11.35 g vs 15.87 ± 7.07 g, respectively, P = 0.040). CONCLUSIONS: The 25-g fructose HBT identified FM in a significantly higher percentage of SIBO-negative patients with IBS than in asymptomatic control individuals, suggesting that FM may correlate with IBS. Education regarding dietary control of foods containing fructose may be useful for the management of patients with IBS.
Breath Tests ; Education ; Food Habits ; Fructose ; Glucose ; Humans ; Hydrogen ; Irritable Bowel Syndrome ; Prevalence ; Prospective Studies

BACKGROUND: We investigated the incidence of active tuberculosis among patients with inflammatory bowel disease (IBD) treated with tumor necrosis factor (TNF) inhibitors, with or without latent tuberculosis infection (LTBI). METHODS: The study was performed at a Korean tertiary referral center between January 2011 and June 2017. In total, 740 patients with IBD who underwent LTBI screening tests and were followed-up for ≥ 1 year after TNF inhibitor treatment initiation were enrolled. LTBI was detected on the basis of tuberculin skin test results, interferon-gamma release assay results, chest X-ray findings, and previous tuberculosis treatment history. The patients were classified into LTBI (n = 84) or non-LTBI (n = 656) group. The risk of developing tuberculosis in each group was assessed on the basis of standardized incidence ratio (SIR) and 95% confidence interval (CI) for active tuberculosis. RESULTS: Mean patient age was 33.1 years, and patients with Crohn's disease were predominant (80.7%). Within 1 year after the initiation of TNF inhibitor treatment, 1 patient in the LTBI group (1/84; 1.2%) and 7 patients in the non-LTBI group (7/656; 1.1%) developed active tuberculosis. The overall 1-year incidence of tuberculosis among the patients was significantly higher than that among the general population (SIR, 14.0; 95% CI, 7.0–28.0), and SIR was not affected by LTBI status (LTBI group: 14.5, 95% CI, 2.0–102.6; non-LTBI group: 14.0, 95% CI, 6.7–29.4). CONCLUSION: Patients with IBD undergoing TNF inhibitor treatment showed a higher 1-year incidence of tuberculosis than the general population irrespective of LTBI status.
Crohn Disease ; Humans ; Incidence* ; Inflammatory Bowel Diseases* ; Interferon-gamma Release Tests ; Latent Tuberculosis* ; Mass Screening ; Skin Tests ; Tertiary Care Centers ; Thorax ; Tuberculin ; Tuberculosis* ; Tumor Necrosis Factor-alpha*

OBJECTIVE: To prospectively evaluate the performance of diffusion-weighted imaging (DWI) to monitor bowel inflammation after medical therapy for Crohn's disease (CD). MATERIALS AND METHODS: Before and following 1–2 years of medical therapy, between October 2012 and May 2015, 18 randomly selected adult CD patients (male:female, 13:5; mean age ± SD, 25.8 ± 7.9 years at the time of enrollment) prospectively underwent MR enterography (MRE) including DWI (b = 900 s/mm²) and ileocolonoscopy. Thirty-seven prospectively defined index lesions (one contiguous endoscopy-confirmed inflamed area chosen from each inflamed anatomical bowel segment; 1–4 index lesions per patient; median, 2 lesions) were assessed on pre- and post-treatment MRE and endoscopy. Visual assessment of treatment responses on DWI in 4 categories including complete remission and reduced, unchanged or increased inflammation, and measurements of changes in apparent diffusion coefficient (ΔADC), i.e., pre-treatment–post-treatment, were performed by 2 independent readers. Endoscopic findings and CD MRI activity index (CDMI) obtained using conventional MRE served as reference standards. RESULTS: ΔADC significantly differed between improved (i.e., complete remission and reduced inflammation) and unimproved (i.e., unchanged or increased inflammation) lesions: mean ± SD (× 10⁻³ mm²/s) of -0.65 ± 0.58 vs. 0.06 ± 0.15 for reader 1 (p = 0.022) and -0.68 ± 0.56 vs. 0.10 ± 0.26 for reader 2 (p = 0.025). DWI accuracy for diagnosing complete remission or improved inflammation ranged from 76% (28/37) to 84% (31/37). A significant negative correlation was noted between ΔADC and ΔCDMI for both readers with correlation coefficients of -0.438 and -0.461, respectively (p < 0.05). CONCLUSION: DWI is potentially a feasible tool to monitor quantitatively and qualitatively bowel inflammation of CD after medical treatment.
Adult ; Crohn Disease* ; Diffusion ; Endoscopy ; Follow-Up Studies ; Humans ; Inflammation* ; Longitudinal Studies* ; Magnetic Resonance Imaging ; Prospective Studies*

BACKGROUND/AIMS: Precutting before endoscopic piecemeal mucosal resection (EPMR) may increase colorectal polyp resection effectiveness. We aimed to identify risk factors for recurrence after conventional EPMR (CEPMR) and precut EPMR (PEPMR) and investigated endoscopic treatment outcomes for recurrent cases. METHODS: The medical records of patients with colorectal polyps treated by EPMR were analyzed. Patients without follow-up surveillance colonoscopies were excluded. RESULTS: Among 359 lesions, the local recurrence rate on the first surveillance colonoscopy was 5.8% (18/312) and 6.4% (3/47) after CEPMR and PEPMR, respectively. Among lesions without recurrence at the first surveillance colonoscopy, the rates of late recurrence on subsequent surveillance colonoscopy were 3.9% (6/152) and 0% after CEPMR and PEPMR, respectively. Larger tumor size was the only independent risk factor for recurrence (odds ratio, 7.93; 95% confidence interval, 1.95–32.30; P<0.001). Endoscopic treatment was performed for all 27 recurrences. A combination of ≥2 endoscopic treatment modalities was used in 19 of 27 recurrences (70.4%). Surveillance colonoscopies were performed in 20 of 27 recurrences after endoscopic treatment. One (5.0%) had a re-recurrence and was treated by surgical resection because recurrence occurred at the appendiceal orifice. Nineteen of 20 lesions (95.0%) could be cured endoscopically, although 3 of the 19 showed second or third recurrences and were treated by repeat endoscopic resection. CONCLUSIONS: The local recurrence rates after CEPMR and PEPMR were similar. Larger tumor size was an independent risk factor for local recurrence after EPMR. Endoscopic treatment of recurrences resulted in high cure rates, although combination methods were necessary in many cases.
Colonoscopy ; Follow-Up Studies ; Humans ; Medical Records ; Polyps ; Recurrence* ; Risk Factors

BACKGROUND/AIMS: The reported rates of current smoking at the time of Crohn’s disease (CD) diagnosis tend to be low in East Asian studies. However, we hypothesized that East Asian patients may be reluctant to disclose their smoking history, likely because of the influence of the Confucian culture. METHODS: We prospectively re-evaluated the smoking status at diagnosis in 1,437 Korean CD patients whose smoking status had been reported in our previous study. RESULTS: After re-evaluation, the current smokers at diagnosis increased from 388 patients (27.0%) to 445 patients (31.0%), indicating that 12.8% (57 of 445 patients) of the current smokers at diagnosis did not disclose their smoking status at their initial evaluation. The proportion of current smokers at diagnosis who had initially concealed their smoking status was significantly higher among the female patients (29.7%, 11/37) compared with the male patients (11.3%, 46/408) (p<0.005) and among the patients who were ≤18 years old at diagnosis (56.4%, 22/39) compared with the patients >18 years old at diagnosis (8.6%, 35/406) (p<0.001). CONCLUSIONS: Subgroups of Korean CD patients, particularly young patients and female patients, are reluctant to disclose their smoking history. Therefore, the suggestion that smoking is not a risk factor for the development of CD in East Asians should be made with caution.
Asian Continental Ancestry Group* ; Crohn Disease* ; Diagnosis ; Female ; Humans ; Male ; Prospective Studies ; Risk Factors ; Smoke* ; Smoking*

As mast cells have been highlighted in the pathogenesis of diarrhea-predominant irritable bowel syndrome, a new term "mastocytic enterocolitis" was suggested by Jakate and colleagues to describe an increase in mucosal mast cells in patients with chronic intractable diarrhea and favorable response to treatment with antihistamines. Although it is not an established disease entity, two cases have been reported in the English medical literature. Here, for the first time in Asia, we report another case of chronic intractable diarrhea caused by gastrointestinal mastocytosis. The patient was a 70-year-old male with chronic intractable diarrhea for 3 months; the cause of the diarrhea remained obscure even after exhaustive evaluation. However, biopsy specimens from the jejunum were found to have increased mast cell infiltration, and the patient was successfully treated with antihistamines.
Aged ; Asia ; Biopsy ; Diarrhea* ; Histamine Antagonists ; Humans ; Irritable Bowel Syndrome ; Jejunum ; Male ; Mast Cells ; Mastocytosis*

BACKGROUND/AIMS: Accurately diagnosing inflammatory bowel disease (IBD) remains a challenge, but is crucial for providing proper management for affected patients. The aim of the present study was to evaluate the frequency of change in diagnosis in Korean patients who were referred to our institution with a diagnosis of IBD. METHODS: We enrolled 1,444 patients diagnosed with ulcerative colitis (UC) and 1,452 diagnosed with Crohn's disease (CD), who had been referred to the Asan Medical Center between January 2010 and December 2014. These patients were assessed and subsequently classified as having UC, CD, indeterminate colitis, possible IBD, or non-IBD. RESULTS: During a median follow-up of 15.9 months, 400 of the 2,896 patients (13.8%) analyzed in this study experienced a change in diagnosis. A change in diagnosis from UC to CD, or vice-versa, was made in 24 of 1,444 patients (1.7%) and 23 of 1,452 patients (1.6%), respectively. A change to a non-IBD diagnosis was the most common modification; 7.5% (108 of 1444) and 12.7% (184 of 1452) of the patients with a referral diagnosis of UC and CD, respectively, were reclassified as having non-IBD. Among the 292 patients who were ultimately determined not to have IBD, 135 (55 UC and 80 CD cases) had received IBD-related medication. CONCLUSIONS: There are diagnostic uncertainties and difficulties in relation to IBD. Therefore, precise assessment and systematic follow-up are essential in the management of this condition.
Chungcheongnam-do ; Cohort Studies* ; Colitis ; Colitis, Ulcerative ; Crohn Disease ; Diagnosis* ; Follow-Up Studies ; Humans ; Inflammatory Bowel Diseases* ; Korea* ; Referral and Consultation

BACKGROUND/AIMS: Although colorectal endoscopic submucosal dissection (ESD)-related perforation is not uncommon, the factors affecting clinical outcomes after perforation have not been investigated. This study was designed to investigate the factors influencing the clinical course of ESD-related colon perforation. METHODS: Forty-three patients with colorectal ESD-related perforation were evaluated. The perforations were classified as endoscopic or radiologic perforations. The patients' medical records and endoscopic pictures were analyzed. RESULTS: The clinical outcomes were assessed by the duration of nil per os, intravenous antibiotics administration, and hospital stays, which were 2.7±1.5, 4.9±2.3, and 5.1±2.3 days, respectively. Multivariate analyses revealed that a larger tumor size, ESD failure, specific endoscopists, and abdominal pain were independently related to a poorer outcome. The time between perforation and clipping was 15.8±25.4 minutes in the endoscopic perforation group. The multivariate analysis of this group indicated that delayed clipping, specific endoscopists, and abdominal pain were independently associated with poorer outcomes. CONCLUSIONS: Tumor size, ESD failure, abdominal pain, and the endoscopist were factors that affected the clinical outcomes of patients with colorectal ESD-related perforation. The time between the perforation and clipping was an additional factor influencing the clinical course of endoscopic perforation. Decreasing this time period may improve outcomes.
Abdominal Pain ; Anti-Bacterial Agents ; Colon ; Humans ; Length of Stay ; Medical Records ; Multivariate Analysis ; Prognosis*

Lymph node metastasis is rare in small (i.e., <10 mm) rectal neuroendocrine tumors (NETs). In addition to tumor size, pathological features such as the mitotic or Ki-67 proliferation index are associated with lymph node metastasis in rectal NETs. We recently treated a patient who underwent endoscopic treatment of a small, grade 1 rectal NET that recurred in the form of perirectal lymph node metastasis 7 years later. A 7-mm-sized perirectal lymph node was noted at the time of the initial endoscopic treatment. The same lymph node was found to be slightly enlarged on follow-up and finally confirmed as a metastatic NET. Therefore, the perirectal lymph node metastasis might have been present at the time of the initial diagnosis. However, the growth rate of the lymph node was extremely low, and it took 7 years to increase in size from 7 to 10 mm. NETs with low Ki-67 proliferation index and without mitotic activity may grow extremely slowly even if they are metastatic.
Diagnosis ; Follow-Up Studies ; Humans ; Lymph Nodes* ; Neoplasm Metastasis ; Neuroendocrine Tumors* ; Rectum