Colon cancer: the 2023 Korean clinical practice guidelines for diagnosis and treatment

Colorectal cancer is the third most common cancer in Korea and the third leading cause of death from cancer. Treatment outcomes for colon cancer are steadily improving due to national health screening programs with advances in diagnostic methods, surgical techniques, and therapeutic agents.. The Korea Colon Cancer Multidisciplinary (KCCM) Committee intends to provide professionals who treat colon cancer with the most up-to-date, evidence-based practice guidelines to improve outcomes and help them make decisions that reflect their patients’ values and preferences. These guidelines have been established by consensus reached by the KCCM Guideline Committee based on a systematic literature review and evidence synthesis and by considering the national health insurance system in real clinical practice settings. Each recommendation is presented with a recommendation strength and level of evidence based on the consensus of the committee.

Colon stenting as a bridge to surgery in obstructive colorectal cancer management

Colonic stent placement is a commonly used bridging strategy for surgery in patients with obstructive colorectal cancer. The procedure involves the placement of a self-expandable metallic stent (SEMS) across the obstructive lesion to restore intestinal patency and alleviate the symptoms of obstruction. By allowing patients to receive surgery in a planned and staged manner with time for preoperative optimization and bowel preparation, stent placement may reduce the need for emergency surgery, which is associated with higher complication rates and poorer outcomes. This review focuses on the role of colon stenting as a bridge to surgery in the management of obstructive colorectal cancer. SEMS as a bridge to surgery for left-sided colon cancer has been demonstrated to be particularly useful; however, further research is needed for its application in cases of right-sided colon cancer. Colon stent placement also has limitations and potential complications including stent migration, re-obstruction, and perforation. However, the timing of curative surgery after SEMS placement remains inconclusive. Considering the literature to date, performing surgery at an interval of approximately 2 weeks is considered appropriate. Therefore, colonic stent placement may be an effective strategy as a bridge to surgery in patients with obstructive colorectal cancer.

Five-year Progress of Gastric MALT Lymphoma Presenting as Gastric Outlet Obstruction / 대한소화기학회지

This paper reports a 70-year-old female with gastric extranodal marginal zone B cell lymphoma of mucosa-associated lymphoid tissue (gastric MALT lymphoma) as a rare case of gastric outlet obstruction. Five years earlier, she initially presented with weight loss and anemia. Esophagogastroduodenoscopy (EGD) revealed multiple gastric and duodenal ulcers with a pyloric deformity, while histology revealed chronic active inflammation and a Helicobacter pylori (H. pylori) infection. Three years earlier, she underwent EGD per the National Cancer Screening Program and was diagnosed with antral and duodenal ulcers. A forceps biopsy specimen from one of the ulcers showed the findings of gastric MALT lymphoma, but she did not visit the hospital for proper management. She visited complaining of a loss of appetite. EGD revealed a gastric outlet obstruction (GOO) caused by antral deformity and pyloric narrowing. A staged workup with CT and PET revealed full-layered, encircling antral wall thickening and several enlarged mesenteric lymph nodes. She was finally diagnosed with a gastric MALT lymphoma at Ann Arbor stage I1E with translocation t(11;18). She was treated with palliative surgery for GOO and systemic chemotherapy with a CHOP regimen. This paper reports a gastric MALT lymphoma that progressed from superficial mucosal lesions to an overt mass with regional lymph node metastasis for five years. (Korean J Gastroenterol 2023;81:265 -269)

Use of device-assisted enteroscopy in small bowel disease: an expert consensus statement by the Korean Association for the Study of Intestinal Diseases

The introduction of device-assisted enteroscopy (DAE) in the beginning of 21st century has revolutionized the diagnosis and treatment of diseases of the small intestine. In contrast to capsule endoscopy, the other main diagnostic modality of the small bowel diseases, DAE has the unique advantages of observing the region of interest in detail and enabling tissue acquisition and therapeutic intervention. As DAE becomes an essential procedure in daily clinical practice, there is an increasing need for correct guidelines on when and how to perform it and what technical factors should be considered. In response to these needs, the Korean Association for the Study of Intestinal Diseases developed an expert consensus statement on the performance of DAE by reviewing the current evidence. This expert consensus statement particularly focuses on the indications, choice of insertion route, therapeutic intervention, complications, and relevant technical points.

Clinical Impact Assessment and Utilization Prospects of the t(11:18) Chromosomal Translocation in Gastric MALT Lymphoma in Koreans: A Single Center Retrospective Analysis / 대한소화기학회지

Background/Aims@#The gastric extranodal marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue (gastric MALT lymphoma) are mostly related to Helicobacter pylori infections. However, chromosomal aberration involving translocation t(11;18) is also frequently reported in these patients. @*Methods@#The study was a retrospective review and analysis of electronic medical records to assess the factors which affect complete remission (CR) in patients with gastric MALT lymphoma. Based on the medical records, subjects with gastric MALT lymphoma were enrolled consecutively from January 2004 to December 2021. @*Results@#Among the 77 subjects who were found with gastric MALT lymphoma in the database, 65 cases with complete records were analyzed. Of these, 66.2% (43/65) were H. pylori positive. Genetic analyses for t(11:18) were done on 41 subjects. The t(11:18) chromosomal translocation with MALT1:BIRC3 fusion was found in 31.7% (13/41) of the subjects. With H. pylori eradication therapy, 75% (21/28) of the subjects without t(11:18) achieved CR. However, only 23.1% (3/13) subjects with t(11:18) could achieve CR (p-value=0.009). In the H. pylori-positive group, 85.7% (18/21) subjects without t(11:18) achieved CR with eradication therapy, but 71.4% (5/7) subjects with t(11:18) failed to achieve CR (p-value=0.004). In the H. pylori-negative group, 42.3% (3/7) of the subjects without t(11:18) achieved CR with eradication therapy. However, 83.3% (5/6) of H. pylori-negative subjects with t(11:18) failed to achieve CR with eradication therapy and needed additional radiotherapy (p-value=0.396). @*Conclusions@#H. pylori negativity and the presence of t(11:18) were both risk factors for failure to achieve CR with H. pylori eradication therapy as the first line of treatment.

Use of Device-Assisted Enteroscopy in Small Bowel Disease: An Expert Consensus Statement by the Korean Association for the Study of Intestinal Diseases / 대한소화기학회지

The introduction of device-assisted enteroscopy (DAE) in the beginning of the 21st century has revolutionized the diagnosis and treatment of diseases of the small intestine. In contrast to capsule endoscopy, the other main diagnostic modality of small bowel diseases, DAE has the unique advantages of allowing the observation of the region of interest in detail and enabling tissue acquisition and therapeutic intervention. As DAE becomes an essential procedure in daily clinical practice, there is an increasing need for correct guidelines on when and how it is to be performed and what technical factors should be taken into consideration. In response to these needs, the Korean Association for the Study of Intestinal Diseases has developed an expert consensus statement on the performance of DAE by reviewing current evidence. This expert consensus statement particularly focuses on the indications, choice of insertion route, therapeutic intervention, complications, and relevant technical points.

The pattern of metachronous recurrence after endoscopic submucosal dissection for gastric adenocarcinoma and dysplasias

Background/Aims@#Metachronous recurrence incidences and risk factors following endoscopic submucosal dissection (ESD) for gastric adenocarcinoma and dysplasias were investigated. @*Methods@#Retrospective review of electronic medical records of patients who underwent gastric ESD at The Catholic University of Korea, Yeouido St. Mary’s Hospital. @*Results@#A total of 190 subjects were enrolled for analysis during the study period. The mean age was 64.4 years-old and the male sex occupied 73.7%. The mean observation period following ESD was 3.45 years. The annual incidence rate of metachronous gastric neoplasms (MGN) was about 3.96%. The annual incidence rate was 5.36% for the low-grade dysplasia group, 6.47% for the high-grade dysplasia group, and 2.74% for the EGC group. MGN was more frequent in the dysplasia group than in the EGC group (p<0.05). For those with MGN development, the mean time interval from ESD to MGN was 4.1 (±1.8) years. By using the Kaplan–Meier model, the estimated mean MGN free survival time was 9.97 years (95% confidence interval, 8.53–11.40) The histological types of MGN were not related to the primary histology types. @*Conclusions@#MGN following ESD developed in 3.96% annually and MGN was more frequent in the dysplasia group. The histological types of MGN did not correlate with those of primary neoplasm.

Diagnosis of inflammatory bowel disease–Asian perspectives: the results of a multinational web-based survey in the 8th Asian Organization for Crohn’s and Colitis meeting

Background/Aims@#Inflammatory bowel disease (IBD) is no longer a rare disease in Asia, thus it needs to prepare recommendations relevant to Asian patients. This study aimed to identify disparities in the process of the diagnosis of IBD in Asian countries/regions. @*Methods@#In line with the 2020 Asian Organization for Crohn’s and Colitis annual meeting, a multinational web-based survey about Asian physicians’ perspectives on IBD was conducted. @*Results@#A total of 384 Asian physicians (99 in China, 93 in Japan, 110 in Korea, and 82 in other Asian countries/regions) treating IBD patients from 24 countries/regions responded to the survey. Most respondents were gastroenterologists working in an academic teaching hospital. About half of them had more than 10 years of clinical experience in caring for patients with IBD. The European Crohn’s Colitis Organisation guideline was used most commonly for the diagnosis of IBD except for Japanese physicians who preferred their own national guideline. The Mayo score and Crohn’s Disease Activity Index were the most commonly used activity scoring systems for ulcerative colitis and Crohn’s disease, respectively. Endoscopy, not surprisingly, was the main investigation in assessing the extent and activity of IBD. On the other hand, there were disparities across countries/regions with regard to the favored modalities of small bowel and perianal evaluation of Crohn’s disease, as well as the use of serologic markers. @*Conclusions@#Results of the present survey revealed practical behaviors of Asian physicians in the diagnosis of IBD. Investigating the reasons for different diagnostic approaches among countries/regions might help us develop Asian guidelines further.

Crohn’s Disease Identified as Granulomatous Tubulointerstitial Nephritis / 대한내과학회지

Crohn’s disease is usually diagnosed according to intestinal symptoms, but extra-intestinal manifestations are important in approximately one-third of cases. Although several extra-intestinal symptoms associated with various organs have been reported, renal involvement is uncommon in patients with Crohn’s disease. Tubulointerstitial nephritis in a patient with Crohn’s disease is usually caused by infection, sarcoidosis, or medications. However, primary tubulointerstitial nephritis caused by Crohn’s disease alone is extremely rare. A 19-year-old male patient was referred to our hospital because of an increase in serum creatinine level. He underwent a kidney biopsy with renal insufficiency. Renal histological findings revealed granulomatous tubulointerstitial nephritis. Thereafter, a colonoscopy was performed with suspicion of Crohn’s disease. Ultimately, he was diagnosed with granulomatous tubulointerstitial nephritis based on Crohn’s disease. The patient had improved gastrointestinal symptoms after the last treatment. This case report presents a rare case of primary tubulointerstitial nephritis caused by Crohn’s disease.

Factors Associated with the Clinical Outcomes of Iatrogenic Colonic Perforation / 대한소화기학회지

Background/Aims@#This study evaluated the incidence of iatrogenic colonic perforation (ICP) in a high-volume center and analyzed the clinical outcomes and associated factors. @*Methods@#As a retrospective study of the electronic medical records, the whole data of patients who underwent colonoscopy from June 2004 to May 2020 were reviewed. @*Results@#During 16 years, 69,458 procedures were performed, of which 60,288 were diagnostic and 9,170 were therapeutic. ICP occurred in 0.027% (16/60,288) for diagnostic colonoscopies and in 0.076% (7/9,170) for therapeutic purposes (p=0.015; hazard ratio 2.878; 95% CI, 1.184-6.997). Fifty-two percent (12 cases) were managed with endoscopic clip closure, and 43.5% (10 cases) required surgery. The reasons for the procedure and the procedure timing appeared to affect the treatment decision. Perforations during therapeutic colonoscopy were treated with surgery more often than those for diagnostic purposes (66.7% [4/6] vs. 37.5% [6/16], p=0.221). Regarding the timing of the procedure, ICP that occurred in the afternoon session was more likely treated surgically (56.3% [9/16] vs. 0/5, p=0.027). Mortality occurred in two patients (2/23, 8.7%). Both were aged (mean age 84.0±1.4 vs. 65.7±10.5, p<0.001) and lately recognized (mean elapsed time [hours], 43.8±52.5 vs. 1.5±3.0, p<0.001) than the surviving patients. @*Conclusions@#ICP occurs in less than 0.1% of cases. The events that occurred during the morning session were more likely managed endoscopically. Age over 80 years and a longer time before perforation recognition were associated with mortality.

Dedicated Cold Snare vs. Traditional Snare for Polypectomy of Diminutive and Small Lesions in a Porcine Model: A Research Group for Endoscopic Instruments and Stents (REIS) Study

Background/Aims@#The aim of this in vivo animal study was to evaluate the effectiveness and safety of dedicated cold snare (DCS) compared with those of traditional snare (TS) for cold snare polypectomy (CSP). @*Methods@#A total of 36 diminutive (5 mm) and 36 small (9 mm) pseudolesions were made by electrocoagulation in the colons of mini-pigs. @*Results@#For the diminutive lesions, there were no significant differences in technical success rate, procedure time, or complete resection rate between the DCS and TS groups; the rate of uneven resection margin in the DCS group was significantly lower than that of the TS group. For small lesions, technical success rate and complete resection rate were significantly higher in the DCS group than in the TS group (100% [18/18] vs. 55.6% [10/18], p=0.003; 94.4% [17/18] vs. 40% [4/10], p=0.006). In addition, the procedure duration was significantly shorter, and the rate of uneven resection margin was significantly lower in the DCS group (28.5 sec vs. 66.0 sec, p=0.006; 11.1% [2/18] vs. 100% [10/10], p<0.001). Two cases of perforation occurred in the DCS group. Multivariate analysis revealed that DCS use was independently associated with complete resection. @*Conclusions@#DCS is superior to TS in terms of technical success, complete resection, and reducing the duration of the procedure for CSP of small polyps.

Dedicated Cold Snare vs. Traditional Snare for Polypectomy of Diminutive and Small Lesions in a Porcine Model: A Research Group for Endoscopic Instruments and Stents (REIS) Study

Background/Aims@#The aim of this in vivo animal study was to evaluate the effectiveness and safety of dedicated cold snare (DCS) compared with those of traditional snare (TS) for cold snare polypectomy (CSP). @*Methods@#A total of 36 diminutive (5 mm) and 36 small (9 mm) pseudolesions were made by electrocoagulation in the colons of mini-pigs. @*Results@#For the diminutive lesions, there were no significant differences in technical success rate, procedure time, or complete resection rate between the DCS and TS groups; the rate of uneven resection margin in the DCS group was significantly lower than that of the TS group. For small lesions, technical success rate and complete resection rate were significantly higher in the DCS group than in the TS group (100% [18/18] vs. 55.6% [10/18], p=0.003; 94.4% [17/18] vs. 40% [4/10], p=0.006). In addition, the procedure duration was significantly shorter, and the rate of uneven resection margin was significantly lower in the DCS group (28.5 sec vs. 66.0 sec, p=0.006; 11.1% [2/18] vs. 100% [10/10], p<0.001). Two cases of perforation occurred in the DCS group. Multivariate analysis revealed that DCS use was independently associated with complete resection. @*Conclusions@#DCS is superior to TS in terms of technical success, complete resection, and reducing the duration of the procedure for CSP of small polyps.

Inhibition of RIPK3 Pathway Attenuates Intestinal Inflammation and Cell Death of Inflammatory Bowel Disease and Suppresses Necroptosis in Peripheral Mononuclear Cells of Ulcerative Colitis Patients

Receptor-interacting serine/threonine-protein kinase (RIPK) 3 is a member of the TNF receptor-I signaling complex and mediates necroptosis, an inflammatory cell death. Ulcerative colitis (UC) is an excessive inflammatory disease caused by uncontrolled T cell activation. The current study is aimed to determine whether RIPK3 inhibitor attenuates UC development inhibiting inflammation and necroptosis using experimental colitis mice model. Dextran sulfate sodium-induced colitis mice were administered RIPK3 inhibitor (3 mg/ml) 3 times and their tissues were analyzed by immunohistochemistry. RIPK3, mixed lineage kinase domain-like (MLKL), phosphorylated MLKL, IL-17, and CD4 in colitis patient colon tissues were detected using confocal microscopy. Protein levels were measured using immunohistochemistry and ELISA. The differentiation of Th17 cells was evaluated using flow cytometry. The expression of proinflammatory cytokines and necroptosis in peripheral blood mononuclear cells from UC patients was decreased markedly by RIPK3 inhibitor treatment. We also observed that the injection of RIPK3 inhibitor improves colitis severity and protects intestinal destruction. RIPK3 inhibitor reduced necroptosis factors and proinflammatory cytokines in the colon and consequently protected colon devastation. The expression of inflammatory mediators in experimental colitis mice splenocytes was decreased significantly by RIPK3 inhibitor treatment. These results suggest that RIPK3 inhibitor ameliorates severity of experimental colitis and reduces inflammation through the inhibition of inflammatory response and necroptosis and support RIPK3-targeting substances for treatment of UC.

Donor Screening for Fecal Microbiota Transplantation / 대한내과학회지

Fecal microbiota transplantation (FMT), which has been established as the standard treatment for recurrent Clostroides difficile infection, may also play a role in the management of other diseases associated with dysbiosis of the gut microbiota. To ensure efficacy and safety of FMT, an appropriate donor screening process is required. The main purpose of donor screening is to check for infectious diseases that could be transmitted to the recipient. The screening process involves a medical history questionnaire, and blood and stool testing. Several randomized clinical trials and large case series on FMT reported no, or few, adverse events related to infection by following this donor screening process. However, there is still concern over the transmission of antibiotic-resistant bacteria. In addition, a low donor acceptance rate due to rigorous screening makes donor recruitment difficult, and also imposes a significant cost burden. A consensus on the most crucial elements of donor screening is needed for wide application of FMT.

Factors Affecting Endoscopic Curative Resection of Gastric Cancer in the Population-Based Screening Era

BACKGROUND/AIMS: Since population-based screening for gastric cancer in Korea was implemented, endoscopic treatment of early gastric cancer has become increasingly popular. This study investigates factors affecting endoscopic curative resection of early gastric cancer in population-based screening for gastric cancer. METHODS: We retrospectively reviewed data of patients with newly diagnosed gastric cancer who underwent treatment at Seoul St. Mary’s Hospital. All patients completed questionnaires about clinical information, including interval between surveillance tests for gastric cancer. RESULTS: Of 469 gastric cancer patients, 147 (31.3%) had undergone curative endoscopic resection, 260 (55.4%) had undergone curative surgical resection, and 62 (13.3%) underwent non-curative resection or were in an inoperable state. Patients with curative endoscopic resection had fewer alarm symptoms/signs than other groups. In multivariate analysis, regular surveillance endoscopy was the only factor predicting curative endoscopic resection (odds ratio [OR], 6.099; 95% confidence interval [CI], 2.532–14.933). In addition, patients undergoing gastric cancer screening had a significantly higher rate of endoscopic curative resection compared with subjects who had never been screened. (1-year interval: OR, 49.969; 95% CI, 6.340–393.827, 2-year interval: OR, 15.283; 95% CI, 1.833–127.406, over 2-year interval: OR, 10.651; 95% CI, 1.248–90.871). Shorter screening test intervals were associated with higher rates of endoscopic curative resection. CONCLUSIONS: Regular surveillance testing was the independent factor predicting curative endoscopic resection of gastric cancer.

Image-Enhanced Endoscopy in Lower Gastrointestinal Diseases: Present and Future

From dye-assisted conventional chromoendoscopy to novel virtual chromoendoscopy, image-enhanced endoscopy (IEE) is continuously evolving to meet clinical needs and improve the quality of colonoscopy. Dye-assisted chromoendoscopy using indigo carmine or crystal violet, although slightly old-fashioned, is still useful to emphasize the pit patterns of the colonic mucosa and predict the histological structures of relevant lesions. Equipment-based virtual chromoendoscopy has the advantage of being relatively easy to use. There are several types of virtual chromoendoscopy that vary depending on the manufacturer and operating principle. IEE plays distinctive roles with respect to histologic characterization of colorectal polyps and prediction of the invasion depth of colorectal cancers. In addition, the newest models of IEE have the potential to increase adenoma and polyp detection rates in screening colonoscopy.

Guideline Recommendation for Endpoints Used in Clinical Trials for Functional Dyspepsia / 대한소화기학회지

Functional dyspepsia is a disease, in which there is no organic lesion but chronic and repetitive postprandial fullness, early satiation, epigastric pain, and epigastric burning. Functional dyspepsia is not life-threatening but its symptoms are relapsing and remitting and persist over a lifetime, limiting the social life and reducing the quality of life. Therefore, the treatment for acute relapsing period may help improve the short-term symptoms. Continuous medication may be needed to improve the long-term symptoms. Research designs to demonstrate the short-term efficacy of therapeutic agents may differ from clinical trials to demonstrate long-term efficacy. There are many difficulties in clinical trial design, implementation, and screening because there are no international standards of clinical trials for functional dyspepsia. The purpose of this guideline recommendation is to develop a standard for clinical trials, such as clinical trial subjects and evaluation methods, in the development of therapeutic agents for functional dyspepsia. The ultimate aim is to enhance the safety and efficacy of therapeutic agents for functional dyspepsia and promote the development of new therapeutic agents.

Application of photodynamic therapy in gastrointestinal disorders: an outdated or re-emerging technique?

Photodynamic therapy (PDT) is a promising therapeutic modality that involves the administration of a photosensitizer followed by local illumination with a specific wavelength of light in the presence of oxygen. PDT is minimally invasive, has high selectivity for cancer, and has good patient compliance due to the simplicity of the procedure; therefore, PDT is widely used as a palliative and salvage treatment in patients with various gastrointestinal malignancies. When used as a salvage treatment for locoregional failures after definitive chemoradiotherapy for esophageal cancer, favorable results have been reported. PDT in conjunction with biliary stenting is a promising palliative treatment for unresectable cholangiocarcinoma, and can be used as an advanced diagnostic and therapeutic strategy in peritoneal dissemination of gastric cancer. Recent clinical reports of PDT for treating non-resectable pancreatic cancer also show promising results. To widen the application of PDT, the integration of PDT with molecular imaging and nanotechnology is being extensively studied. Based on these new developments, PDT is likely to re-emerge as a valuable technique in the treatment of diverse gastrointestinal diseases.

Endoscopic Appearances with a High Probability of Positive Biopsy in Follow-up Endoscopy of Gastric Mucosa-associated Lymphoid Tissue Lymphoma

BACKGROUND/AIMS: Remission of gastric mucosa-associated lymphoid tissue (MALT) lymphoma is difficult due to pleomorphic and multifocal endoscopic findings. We investigated the relationship between endoscopic appearances and histological findings of patients followed up after curative treatment for the tumor. MATERIALS AND METHODS: This retrospective study included 25 consecutive patients diagnosed with gastric MALT lymphoma, who were treated and underwent serial follow-up endoscopies with biopsies from June 2009 to March 2014 in Seoul St. Mary's Hospital. We reviewed the follow-up endoscopic findings at least 2 months after Helicobacter pylori eradication or chemoradiotherapy. Target biopsy sites were categorized according to their endoscopic appearance. RESULTS: The mean follow-up period was 17.6 months; 76 endoscopies and 238 biopsies were performed. Positive biopsies were observed in 50 cases (21.0%). Tumor positivity was high in ulcerated lesions (2/3, 66.7%), erosion (1/5, 20.0%), discoloration (32/89, 36.0%), mucosal thickening (10/41, 24.4%) and ulcer scars (3/21, 14.3%). Conversely, lesions appearing normal showed low positivity (1/68, 1.5%) and was significantly lower compared with the aforementioned lesions (P<0.001). CONCLUSIONS: Endoscopic appearances of depression, discoloration, mucosal thickening and ulcer scars were more likely to have tumor cells and should be targeted during follow up for gastric MALT lymphoma.

The Efficacy of Hypnotherapy in the Treatment of Irritable Bowel Syndrome: A Systematic Review and Meta-analysis

BACKGROUND/AIMS: Hypnotherapy is considered as a promising intervention for irritable bowel syndrome (IBS), but the evidence is still limited. The aims of this study were to conduct a systematic review and meta-analysis to estimate the efficacy of hypnotherapy for the treatment of IBS. METHODS: A literature search was performed using MEDLINE (PubMed), Embase, PsycINFO and the Cochrane Central Register of Controlled Trials (CENTRAL database). Only randomized controlled trials that compared hypnotherapy with any other conventional treatment or no treatment in patients with IBS were included. Studies had to report outcomes as IBS symptom score or quality of life. The mean change in outcome score was used to pool these outcomes for the meta-analysis. Data were synthesized using the standardized mean difference for continuous data. RESULTS: Seven randomized controlled trials (6 papers) involving 374 patients with IBS were identified. Performance bias was high in all trials because it was impossible to blind participants and therapists in this type of intervention. The outcomes in this meta-analysis were evaluated at 3 months for short-term effects and at 1 year for long-term effects. The change in abdominal pain score at 3 months was significant in the hypnotherapy group (standardized mean difference, -0.83; 95% CI, -1.65 to -0.01). Three of the 4 trials showed greater improvement in overall gastrointestinal symptoms in the hypnotherapy group. CONCLUSIONS: This study provides clearer evidence that hypnotherapy has beneficial short-term effects in improving gastrointestinal symptoms of patients with IBS.