Abstract
The meta-analysis aimed to investigate the prevalence of gallstones (GS) in Inflammatory bowel disease (IBD), especially ulcerative colitis (UC). A systematic and thorough search was conducted on online electronic databases (PubMed/Medline, Cochrane Library, and Google Scholar) from the databases' inception to April 30th, 2022. Review Manager 5.4.1 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen) was used for all statistical analyses and forest plots. Only studies that met inclusion criteria were selected. The selected studies were pooled using a random-effect model and the results were reported in the odds ratio (OR) with their corresponding 95% confidence interval (CI). Ten studies met the final inclusion criteria and were analyzed. Patients with UC had significantly higher prevalence of GS than those in the control group (OR=1.67 [1.32-2.11]; p < 0.0001; I2=58%). There was also significant prevalence of GS in Crohn’s disease (CD) than those in control group (OR=2.22 [1.82, 2.69]; p < 0.00001; I2=31%). Analysis also showed the prevalence of GS in studies conducted in Asia (OR=2.00 [1.48, 2.70]; p < 0.00001; I2=80%) and Europe (OR= 1.84 [1.32, 2.55]; p = 0.0003; I2=45%) compared to the control group. This study provided a conclusive answer to whether GS is significant in UC or not. Our meta-analysis provides a well-powered estimate that there is a prevalence of GS in UC. CD is also significantly associated with GS.
Keywords: gallstones, ulcerative colitits, crohn's disease, inflmammtory bowel disease, prevalence
Introduction and background
Inflammatory bowel disease (IBD) has been a global healthcare problem [1]. Studies estimate that 2.5-3 million people suffer from IBD in Europe [2]. The health economic burden and permanent work disability due to IBD is high in Europe, with a total yearly direct healthcare cost of 4.6-5.6 billion euros [3]. IBD is a hypernym of Crohn’s Disease (CD) and ulcerative colitis (UC), which are distinct chronic bowel-relapsing inflammatory disorders [4]. UC affects the superficial mucosa, starting with the rectum, in a continuous pattern and is limited to the colon. CD is characterized by transmural inflammation that can affect any part of the GI tract from mouth to anus [2]. IBD has been associated with several extra-intestinal manifestations seen in 25% to 40% of patients with IBD patients, including peripheral arthritis, erythema nodosum, and episcleritis [5]. Those involving the extrahepatic biliary tract include gallstone disease [6].
The relationship between GS and CD has been well recognized since the 1960s, and this prevalence of CD has been estimated to be 13-14%, as reported in different series [7-10] but this same relation is subjected to variability when assessing UC. A meta-analysis by Zhang et al. clearly established a relationship between GS and CD but showed no significant association with UC [11]. Since this meta-analysis, a number of other observational studies have been published that presented varying associations of GS between UC and CD. Therefore, we aim to pool all the published data assessing the prevalence of gallstones in UC and CD separately to remove existing discrepancies amongst studies.
In the previous meta-analysis [11], studies included were from areas located in Europe. However, the epidemiology of this disease in Westernized nations is changing throughout the world at the turn of the 21st century [12]. Now, newer epidemiological studies suggest that incidence might be rising rapidly in South America, Eastern Europe, Asia, and Africa [13]. Any interruption in excretion and reabsorption of bile acids from the gut can result in the precipitation of gallstones [14-16]. Thus, an updated meta-analysis is conducted, which includes studies from other parts of the world, including Asia. The previous meta-analysis was limited by the fact that it included studies with smaller samples [11]. So we aimed to conduct an updated meta-analysis with recent studies having a much larger sample size for better, robust, and more reliable results.
The primary objective of this updated meta-analysis is to find out the prevalence of GS in patients with CD and UC. The secondary objective is to investigate if there is any geographical significance in the association of GS.
Review
Materials and Methods
Search Strategy and Databases
Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) guidelines and protocols were followed for conducting this meta-analysis [17]. An online electronic search from databases namely, PubMed/Medline, Cochrane Library, and Google Scholar was conducted from the inception of databases to April 30th, 2022 with only English language-based literature. In addition, studies that were cited by previous meta-analyses, cohort studies, and review articles were screened as well to identify any relevant studies. A detailed literature search is provided in Table 1.
Table 1. Details of the search strategy.
| Search Engine | Search Strategy |
| Pubmed/Medline | (("crohn*"[All Fields] AND ("disease"[MeSH Terms] OR "disease"[All Fields] OR "diseases"[All Fields] OR "disease s"[All Fields] OR "diseased"[All Fields])) OR "IBD"[All Fields] OR ("inflamm"[All Fields] AND ("bowel s"[All Fields] OR "bowell"[All Fields] OR "intestines"[MeSH Terms] OR "intestines"[All Fields] OR "bowel"[All Fields] OR "bowels"[All Fields]))) AND ("gallstones"[MeSH Terms] OR "gallstones"[All Fields] OR ("gall"[All Fields] AND "stones"[All Fields]) OR "gall stones"[All Fields] OR "bilestone"[All Fields] OR ("gallstones"[MeSH Terms] OR "gallstones"[All Fields] OR ("biliary"[All Fields] AND "calculus"[All Fields]) OR "biliary calculus"[All Fields]) OR ("urinary bladder calculi"[MeSH Terms] OR ("urinary"[All Fields] AND "bladder"[All Fields] AND "calculi"[All Fields]) OR "urinary bladder calculi"[All Fields] OR "cystolith"[All Fields] OR "cystoliths"[All Fields]) OR ("calculi"[MeSH Terms] OR "calculi"[All Fields] OR "concretion"[All Fields] OR "concretions"[All Fields]) OR ("cholelithiasis"[MeSH Terms] OR "cholelithiasis"[All Fields] OR "cholelithiases"[All Fields]) OR ("extra-intestinal"[All Fields] AND ("manifest"[All Fields] OR "manifestating"[All Fields] OR "manifestation"[All Fields] OR "manifestations"[All Fields] OR "manifested"[All Fields] OR "manifesting"[All Fields] OR "manifestion"[All Fields] OR "manifestions"[All Fields] OR "manifests"[All Fields]))) |
| Cochrane | (Crohn* disease OR IBD OR inflamm * bowel) AND (gall stones OR bilestone OR biliary calculus OR cystolith OR concretion OR cholelithiasis OR extra-intestinal manifestation) |
| Google Scholar | (Crohn* disease OR IBD OR inflamm * bowel) AND (gall stones OR bilestone OR biliary calculus OR cystolith OR concretion OR cholelithiasis OR extra-intestinal manifestation) |
Study Selection
All studies were included if they met the following eligibility criteria: (a) articles describing patients of UC, CD, or both; (b) GS should be present as an only or one of the variables that were being assessed; (c) No previous history of GS or ileal surgery should be present in the experimental or control group; (d) articles should have a defined number of patients and control.
Furthermore, the strategy for research can be given as PECOS: (1) P (Population): Inflammatory patients; (2) E (Exposure): Gallstones; (3) C (Control): cancer patients without GS; (4) O (Outcome): Prevalence of GS in IBD patients; (5) S (Studies): randomized controlled trials, cross-sectional and cohort studies published in English only.
Quality Assessment and Data Extraction From Selected Studies
Two reviewers independently performed a literature search from electronic databases and a third author was consulted to resolve any discrepancies. References of the papers were exported to the EndNote Reference Library v.X7 (Clarivate Analytics, London) and duplicates were identified and removed.
Two separate reviewers independently extracted data and assessed the quality of included studies. Newcastle-Ottawa Scale (NOS) was used to assess the quality of the selected studies. A score >6 was considered a low bias and a score 6 or less was deemed as a significant bias.
Statistical Analysis
All statistical and analytical tests were performed using Review Manager v. 5.4.1 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen). All the extracted data from selected studies were pooled using random-effects model. Analyses of results were done by calculating the odds ratio (OR) with corresponding 95% confidence intervals (CI). Leave-one-out sensitivity analysis was done to see if any study had a significant effect on overall results. As per the Cochrane handbook, the value of heterogeneity I2 = 25-60% was considered as moderate; 50-90% as substantial; and 75-100% as considerably high heterogeneity, and p <0.1 indicated significant heterogeneity [18]. A p-value of less than 0.05 was considered significant for all analyses. The chi-square test was used to assess any differences between the subgroups.
Results
Literature Search Results
The initial literature search from the electronic online databases brought up 1,060 potential research studies. After removal of duplicates and exclusions based on titles and abstracts, the full text of 112 studies was read for possible inclusion. A total of 10 studies remained for quantitative analysis. The summary and results of literature search are given in Figure 1.
Figure 1. Summary of the study selection process according to PRISMA guidelines.
PRISMA: Preferred Reporting Items for Systematic Review and Meta-Analyses
Study Characteristics
Table 2 provides the basic characteristics of included studies. Ten studies included a total of 1,193,902 patients. The IBD group included 53,542 patients, out of which 1,155 (2.16%) had GS. The control group comprised 1,140,360 patients, and the frequency of GS in control was 8,921 (0.78%). Two separate analyses for UC and CD were conducted. The UC group included 37,567 patients, out of which 693 (1.84%) had GS. Their control group comprised 1,139,113 patients, out of which 8,588 (0.75%) consisted of GS. The CD group included 15,975 patients, out of which 462 (2.89%) had GS. The control group comprised 1,139,292 patients, out of which 8,773 (0.77%) were positive for GS.
Table 2. Basic characteristics of the selected studies.
UC, ulcerative colitis; CD, Crohn's disease; IBD, inflammatory bowel disease
| Study Name | Year | Study design | Country | Basis of Diagnosis | Mean Age (years) | Female IBD patients (%) | No. IBD Patients (n) | No. Controls (Non-IBD) (n) | Odds Ratio (95% CI) | P value | NOS score |
| Whorwell et al. [9] | 1984 | Case-control | United Kingdom | Medical records | 53 | 63.16 | 38 | 38 | 6.07 (1.56-23.55) | 0.0092 | 7 |
| Lorusso et al. [8] | 1990 | Case-control | Italy | Medical records | 41 (UC) 39 (CD) | 40.3 | 159 | 2453 | 1.11 (0.66- 1.87) | 0.6967 | 9 |
| Lapidus et al. [7] | 1999 | Cohort | Sweden | Medical records | N/A* | 57.3 | 131 | 556 | 2.42 (1.55-3.76) | 0.0001 | 8 |
| Bargiggia et al. [19] | 2003 | Cohort | Italy | Medical records | 38 (CD) 39 (UC) | 48.5 | 511 | 145 | 2.25 (1.05-4.82) | 0.0379 | 9 |
| Parente et al. [20] | 2007 | Case-control | Italy | Medical records | 34.7 (CD) 38.7 (UC) | 45.5 | 600 | 600 | 1.80 (1.14- 2.84) | 0.0110 | 9 |
| Ha et al. [21] | 2015 | Cohort | Republic of Korea | Medical records | 42.66 | 50.6 | 87 | 261 | 5.06 (1.99, 12.84) | 0.0006 | 9 |
| Jeong et al. [22] | 2017 | Cohort | Republic of Korea | Medical records | 47.7 | 43.4 | 311 | 622 | 2.18 (1.22-3.88) | 0.0083 | 9 |
| Chen et al. [23] | 2018 | Cohort | Taiwan | ICD-9 codes | 47.7 | 52.6 | 8186 | 8186 | 1.47 (1.22-1.78) | 0.0001 | 9 |
| Yang et al. [24] | 2018 | Cross-sectional | Republic of Korea | ICD-10 codes | 34 (CD) 45.7 (UC) | 36.5(CD) 41.9(UC) | 43,281 | 1,127,261 | 2.08 (1.92-2.26) | 0.0000 | 9 |
| Sturdik et al. [25] | 2019 | Case-control | Slovak Republic | Medical records | 40 | 47.9 | 238 | 238 | 1.42 (0.79-2.53) | 0.2414 | 8 |
Publication Bias
No publication bias was noted in our meta-analysis on inspection of the funnel plot as shown in Figure 2.
Figure 2. Funnel plot for publication bias.
Quality Assessment of Included Studies
Quality assessment for observational studies was done by Newcastle-Ottawa Scale. All the studies were of high quality and had a low risk of bias. Detailed assessment with individual components is shown in Table 3.
Table 3. Details of Newcastle-Ottawa Scale for observational studies.
| Studies | Selection (Maximum 4) | Comparability (Maximum 2) | Outcome (Maximum 3) | Total score | |||||
| Representativeness of the Exposed Cohort | Selection of the Non-Exposed Cohort | Ascertainment of Exposure | Demonstration That Outcome of Interest Was Not Present at Start of Study | Comparability of Cohorts on the Basis of the Design or Analysis | Assessment of Outcome | Was Follow-Up Long Enough for Outcomes to Occur | Adequacy of Follow Up of Cohorts | ||
| Lapidus et al. [7] | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| Bargiggia et al. [19] | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 9 |
| Ha et al. [21] | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 9 |
| Jeong et al. [22] | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 9 |
| Chen et al. [23] | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 9 |
| Whorwell et al. [9] | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| Lorusso et al. [8] | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 9 |
| Parente et al. [20] | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 9 |
| Sturdik et al. [25] | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 9 |
| Yang et al. [24] | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 9 |
Results of the Meta-Analysis
(i) Ulcerative colitis: Seven studies reported data for the prevalence of GS in UC. Pooled result (Figure 3) showed statistically significant prevalence of GS in UC than that of in control group (OR=1.67 [1.32, 2.11]; p < 0.0001; I2=58%).
Figure 3. Forest plot summarizing analysis of prevalence of gallstone in patients with ulcerative colitis.
95% CI, 95% confidence interval
(ii) Crohn’s disease: Eight studies reported data for the prevalence of GS in CD. Pooled result (Figure 4) showed statistically significant prevalence of GS in CD than that of in control group (OR= 2.22 [1.82, 2.69]; p < 0.00001; I2=31%).
Figure 4. Forest plot summarizing analysis of prevalence of gallstone in patients with Crohn’s disease .
95% CI, 95% confidence interval
(iii) Geographical location: Out of 10 studies, four were from Asia (three were from the Republic of Korea and one from Taiwan), and five were from Europe (three were from Italy, one from the Slovak Republic, one from Sweden, and one from the United Kingdom). Analysis (Figure 5) showed that there was higher prevalence of GS in studies conducted in Asia (OR= 2.00 [1.48, 2.70]; p < 0.00001; I2=80%) and in Europe (OR= 1.84 [1.32, 2.55]; p =0.0003; I2=45%) than the control group.
Figure 5. Forest plot summarizing analysis of prevalence of gallstones in Asia and Europe.
95% CI, 95% confidence interval
Sensitivity Analysis
A sensitivity analysis was conducted to assess the influence of each study on the overall effect by excluding one study at a time, followed by the generation of pooled OR for the rest of the studies. It is vital to note that Yang et al. had around a million population in its study but still removing it in ulcerative colitis (OR= 1.63 [1.15, 2.31]; p =0.006; I2=51%), Crohn’s disease (OR= 2.00 [1.62, 2.47]; p < 0.00001; I2=0%) and in Asia (OR= 2.20 [1.21, 4.02]; p =0.01; I2=74%) did not change the overall outcome which showed that the outcome was not influenced by this study [24]. On leave-one-out analysis, no significant change was seen in the p-value after removing studies one by one. This showed that the results were robust.
Discussion
This 53,542 IBD patients’ analysis shows an instrumental result regarding the prevalence of GS in IBD patients. Although a previously published meta-analysis by Zhang et al. (2015) has explored this association, their results were limited by the small sample size (1,439 IBD patients). It also failed to establish any significant association between GS and UC [11].
A very prominent finding in our analysis is the association between GS and UC. Some articles have suggested and presented a statistically significant prevalence of GS in UC [8], but no previous meta-analysis has confirmed this outcome. This analysis provides a well-established result, highlighting the prevalence of GS in CD and UC. Based on our findings, it is suggestive that IBD patients have a risk of developing GS. Physicians should provide medication and proper lifestyle modification, which will improve the quality of life of IBD patients and act as prophylaxis for GS prevention.
It is pivotal to provide reasons for GS in CD and UC. Enterohepatic circulation is responsible for the excretion of bile acids by the liver into the small intestine, and then cholesterol is excreted through bile [14]. Any interruption in the mechanism of excretion and reabsorption of bile acids from the intestine results in the precipitation of gallstones. CD disrupts the enterohepatic circulation in the terminal ileum and can slow down the gallbladder contractility; therefore, it can lead to the formation of gallstones [15,16].
Several controversial studies show different results regarding the prevalence of GS in UC; however, a study conducted by Holmquist et al. showed that an affected ascending colon in UC could increase fecal bile excretion; therefore, loss of excess bile will result in precipitation of GS [26]. Several studies also showed gallstone development following the colectomy for UC [27], suggesting that the colon plays a minor role in bile reabsorption. However, the mechanism in the development of GS in UC is still disputed.
The studies showed the influence of the geographical variations of GS prevalence in IBD, highlighting the increasing incidence of GD in the Asia and Europe region [12-13]. Although no large-scale and diverse studies have been conducted that can profoundly state regional influence on GS. Our subgroup analysis shows that there is statistical significance in regions of Asia and Europe for the presence of GS.
Based on our findings, it is suggestive that IBD patients have a risk of developing GS, which ultimately leads to complications such as choledocholithiasis, acute cholangitis, and gallstone ileus, which in some cases can be life-threatening as it may proceed to acute biliary pancreatitis and gallbladder carcinoma [28]. This research will help physicians to better manage IBD patients for future occurrence of GS by an annual screening of the gallbladder via ultrasound. Also, physicians can prophylactically administer IBD patients with lipid-lowering agents such as statin drugs, along with a restricted cholesterol diet. A selected subgroup of patients with asymptomatic gallstones but who are at high risk of developing symptoms of gallbladder cancer or biliary pancreatitis can also be managed by prophylactic cholecystectomy [28].
Our study is limited by some factors such as (a) all studies were observational in nature, the results of which can have some bias (b) controls selected by some studies were based on hospital settings which might have overestimated gallstone formation. Further research is needed especially with more randomized studies.
Conclusions
This study provides a conclusive answer to whether GS is significant in UC or not. Our meta-analysis provides a well-powered estimate that there is a prevalence of GS in UC. CD is also significantly associated with GS. Although patients of CD and UC have overlapping clinical symptoms, patients with predominant UC symptoms also have a possibility of gallstones and should be kept in mind when presenting with right upper quadrant pain and other symptoms of cholelithiasis.
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Footnotes
The authors have declared that no competing interests exist.
References
- 1.Unravelling the pathogenesis of inflammatory bowel disease. Xavier RJ, Podolsky DK. Nature. 2007;448:427–434. doi: 10.1038/nature06005. [DOI] [PubMed] [Google Scholar]
- 2.Inflammatory bowel disease. Shapiro JM, Subedi S, LeLeiko NS. Pediatr Rev. 2016;37:337–347. doi: 10.1542/pir.2015-0110. [DOI] [PubMed] [Google Scholar]
- 3.The burden of inflammatory bowel disease in Europe. Burisch J, Jess T, Martinato M, Lakatos PL. J Crohns Colitis. 2013;7:322–337. doi: 10.1016/j.crohns.2013.01.010. [DOI] [PubMed] [Google Scholar]
- 4.Inflammatory bowel disease: pathogenesis. Zhang YZ, Li YY. World J Gastroenterol. 2014;20:91–99. doi: 10.3748/wjg.v20.i1.91. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.The extra-intestinal complications of Crohn's disease and ulcerative colitis: a study of 700 patients. Greenstein AJ, Janowitz HD, Sachar DB. Medicine (Baltimore) 1976;55:401–412. doi: 10.1097/00005792-197609000-00004. [DOI] [PubMed] [Google Scholar]
- 6.Hepatobiliary disorders in inflammatory bowel disease. Christophi C, Hughes ER. https://pubmed.ncbi.nlm.nih.gov/3881836/ Surg Gynecol Obstet. 1985;160:187–193. [PubMed] [Google Scholar]
- 7.The prevalence of gallstone disease in a defined cohort of patients with Crohn's disease. Lapidus A, Bångstad M, Aström M, Muhrbeck O. Am J Gastroenterol. 1999;94:1261–1266. doi: 10.1111/j.1572-0241.1999.01076.x. [DOI] [PubMed] [Google Scholar]
- 8.Cholelithiasis in inflammatory bowel disease. A case-control study. Lorusso D, Leo S, Mossa A, Misciagna G, Guerra V. Dis Colon Rectum. 1990;33:791–794. doi: 10.1007/BF02052328. [DOI] [PubMed] [Google Scholar]
- 9.Ultrasound survey of gallstones and other hepatobiliary disorders in patients with Crohn's disease. Whorwell PJ, Hawkins R, Dewbury K, Wright R. Dig Dis Sci. 1984;29:930–933. doi: 10.1007/BF01312482. [DOI] [PubMed] [Google Scholar]
- 10.Gallstone disease and related risk factors in patients with Crohn disease: analysis of 330 consecutive cases. Fraquelli M, Losco A, Visentin S, Cesana BM, Pometta R, Colli A, Conte D. Arch Intern Med. 2001;161:2201–2204. doi: 10.1001/archinte.161.18.2201. [DOI] [PubMed] [Google Scholar]
- 11.Is gallstone disease associated with inflammatory bowel diseases? A meta-analysis. Zhang FM, Xu CF, Shan GD, Chen HT, Xu GQ. J Dig Dis. 2015;16:634–641. doi: 10.1111/1751-2980.12286. [DOI] [PubMed] [Google Scholar]
- 12.Understanding and preventing the global increase of inflammatory bowel disease. Kaplan GG, Ng SC. Gastroenterology. 2017;152:313–321. doi: 10.1053/j.gastro.2016.10.020. [DOI] [PubMed] [Google Scholar]
- 13.Worldwide incidence and prevalence of inflammatory bowel disease in the 21st century: a systematic review of population-based studies. Ng SC, Shi HY, Hamidi N, et al. Lancet. 2017;390:2769–2778. doi: 10.1016/S0140-6736(17)32448-0. [DOI] [PubMed] [Google Scholar]
- 14.Gallstones. Lammert F, Gurusamy K, Ko CW, et al. Nat Rev Dis Primers. 2016;2:16024. doi: 10.1038/nrdp.2016.24. [DOI] [PubMed] [Google Scholar]
- 15.Cholesterol and bile acid biodynamics after total small bowel resection and bile diversion in humans. Férézou J, Beau P, Parquet M, Champarnaud G, Lutton C, Matuchansky C. Gastroenterology. 1993;104:1786–1795. doi: 10.1016/0016-5085(93)90660-5. [DOI] [PubMed] [Google Scholar]
- 16.Impaired fatty-meal-stimulated gallbladder contractility in patients with Crohn's disease. Murray FE, McNicholas M, Stack W, O'Donoghue DP. Clin Sci (Lond) 1992;83:689–693. doi: 10.1042/cs0830689. [DOI] [PubMed] [Google Scholar]
- 17.The PRISMA extension statement for reporting of systematic reviews incorporating network meta-analyses of health care interventions: checklist and explanations. Hutton B, Salanti G, Caldwell DM, et al. Ann Intern Med. 2015;162:777–784. doi: 10.7326/M14-2385. [DOI] [PubMed] [Google Scholar]
- 18.Updated guidance for trusted systematic reviews: a new edition of the Cochrane Handbook for Systematic Reviews of Interventions. Cumpston M, Li T, Page MJ, Chandler J, Welch VA, Higgins JP, Thomas J. Cochrane Database Syst Rev. 2019;10:0. doi: 10.1002/14651858.ED000142. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.Sonographic prevalence of liver steatosis and biliary tract stones in patients with inflammatory bowel disease: study of 511 subjects at a single center. Bargiggia S, Maconi G, Elli M, et al. J Clin Gastroenterol. 2003;36:417–420. doi: 10.1097/00004836-200305000-00012. [DOI] [PubMed] [Google Scholar]
- 20.Incidence and risk factors for gallstones in patients with inflammatory bowel disease: a large case-control study. Parente F, Pastore L, Bargiggia S, et al. Hepatology. 2007;45:1267–1274. doi: 10.1002/hep.21537. [DOI] [PubMed] [Google Scholar]
- 21.Increased risk of asymptomatic gallstones in patients with ulcerative colitis. Ha JH, Park YS, Seon CS, et al. Intest Res. 2015;13:122–127. doi: 10.5217/ir.2015.13.2.122. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Gallstone prevalence and risk factors in patients with ulcerative colitis in Korean population. Jeong YH, Kim KO, Lee HC, et al. Medicine (Baltimore) 2017;96:0. doi: 10.1097/MD.0000000000007653. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23.Association between inflammatory bowel disease and cholelithiasis: a nationwide population-based cohort study. Chen CH, Lin CL, Kao CH. Int J Environ Res Public Health. 2018;15:513. doi: 10.3390/ijerph15030513. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24.Prevalence of extraintestinal manifestations in Korean inflammatory bowel disease patients. Yang BR, Choi NK, Kim MS, Chun J, Joo SH, Kim H, Lee J. PLoS One. 2018;13:0. doi: 10.1371/journal.pone.0200363. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25.Pathophysiology and risk factors for cholelithiasis in patients with Crohn's disease. Sturdik I, Krajcovicova A, Jalali Y, et al. Physiol Res. 2019;68:0–82. doi: 10.33549/physiolres.934302. [DOI] [PubMed] [Google Scholar]
- 26.Bile acid malabsorption in children and adolescents with chronic colitis. Holmquist L, Andersson H, Rudic N, Ahrén C, Fällström SP. Scand J Gastroenterol. 1986;21:87–92. doi: 10.3109/00365528609034628. [DOI] [PubMed] [Google Scholar]
- 27.Increased risk of gallstone disease following colectomy for ulcerative colitis. Mark-Christensen A, Brandsborg S, Laurberg S, et al. Am J Gastroenterol. 2017;112:473–478. doi: 10.1038/ajg.2016.564. [DOI] [PubMed] [Google Scholar]
- 28.Management of gallstones and its related complications. Portincasa P, Di Ciaula A, de Bari O, Garruti G, Palmieri VO, Wang DQ. Expert Rev Gastroenterol Hepatol. 2016;10:93–112. doi: 10.1586/17474124.2016.1109445. [DOI] [PubMed] [Google Scholar]





