Search tips
Search criteria 


Logo of wjgLink to Publisher's site
World J Gastroenterol. 2010 May 7; 16(17): 2075–2079.
Published online 2010 May 7. doi:  10.3748/wjg.v16.i17.2075
PMCID: PMC2864832

Management of gallstones and gallbladder disease in patients undergoing gastric bypass


The appropriate management of gallstones and gallbladder disease in patients undergoing gastric bypass remains unknown. Several therapeutic modalities are used and include performing cholecystectomy on all patients at the time of gastric bypass, performing concomitant cholecystectomy only when patients have gallstones and performing cholecystectomy only in the presence of both symptoms and gallstones. Some groups administer ursodeoxycholic acid for gallstone prevention in the postoperative period. All treatment modalities are analyzed and their results and rationality are discussed.

Keywords: Gallbladder, Gastric bypass, Morbid obesity, Gallstones, Cholecystectomy


Rapid weight loss after bariatric surgery is one of many known risk factors for gallstone development, along with age, female gender, parity, race, obesity, genetics, very-low-calorie diets, short bowel syndrome, gallbladder motor dysfunction, diabetes, drugs and gastrointestinal surgery, among many others[1-25].

Traditionally cholecystectomy was indicated only in the presence of both gallstones and symptoms, but recently some have advocated elective cholecystectomy in selected cases in the absence of symptoms and even in the absence of gallstones[26-29].

Sustained weight loss after gastric bypass is achieved by a combination of gastric restriction and a variable degree of malabsortion[30-32] and has therefore a greater risk for gallstone development than purely restrictive procedures like adjustable gastric banding[33-35]. The appropriate management of gallstones and gallbladder disease in these patients is still under debate and several therapeutic modalities are used[36], including simultaneous cholecystectomy to all patients at the time of gastric bypass, regardless of the presence or absence of gallstones and/or symptoms (prophylactic approach)[37], simultaneous cholecystectomy only to patients with gallstones (elective or selective approach)[38] and expectant management with or without the prophylactic administration of ursodeoxycholic acid until symptoms develop (conventional approach)[39].

The objective of the paper is to discuss the rationale and the results obtained with these therapeutic modalities.


This consists of performing simultaneous cholecystectomy on all patients at the time of gastric bypass, regardless of the presence or absence of gallstones and/or symptoms.

The rationale behind this approach is based on the elevated incidence of gallstone development after gastric bypass compared to the normal population and the low sensitivity and specificity of ultrasonography for detecting gallstones in patients with morbid obesity[37,40-42]. A minimal morbidity rate with the addition of cholecystectomy is required.

In the series of Fobi et al[37] abnormal findings in the gallbladder were found in 75% of surgical specimens despite a negative preoperative ultrasound. Most of these patients had gallstones but other findings include cholesterolosis and cholecystitis. The addition of cholecystectomy to open gastric bypass added only an average of 15 min and the authors report no specific morbidity related to it.

Nougou et al[43] found some pathology in nearly 82% of specimens after simultaneous cholecystectomy with laparoscopic gastric bypass. 8.3% of patients did not undergo simultaneous cholecystectomy because it was judged to be dangerous. In the remaining patients, cholecystectomy added only 19 min on average to the procedure, with no extra ports addition. The authors do not report specific morbidity related to cholecystectomy.

Guadalajara et al[41] performed simultaneous cholecystectomy on 89 patients undergoing open gastric bypass and found a postoperative incidence of gallstones of 24% while the preoperative ultrasound incidence was only 16%.

Liem et al[44] performed simultaneous cholecystectomy on all patients undergoing open gastric bypass and found an incidence of gallbladder pathology of 80%.

A summary of these results is presented in Table Table11.

Table 1
Results for cholecystectomy


This consists of performing simultaneous cholecystectomy only on patients with asymptomatic gallstones diagnosed pre or intraoperatively.

The rationale behind this approach is based on an assumed higher incidence of symptomatic gallbladder disease in patients with gallstones in comparison to those without them. Some groups administer prophylactic ursodeoxycholic acid to patients without gallstones and therefore not submitted to concomitant cholecystectomy. A low morbidity rate is also required to support this approach.

Hamad et al[38] performed simultaneous cholecystectomy on 16.9% of patients at the time of gastric bypass. Operative times were significantly longer for patients undergoing simultaneous cholecystectomy and total hospital stay was almost doubled in comparison to gastric bypass without concomitant cholecystectomy. A significantly higher major morbidity rate was observed for patients undergoing simultaneous cholecystectomy but no specific morbidity was directly related to it. The most common pathological finding in the specimens was cholecystitis (99% of the cases). All patients without simultaneous cholecystectomy received 300 mg of ursodeoxycholic acid twice a day orally for a 6 mo period. During follow up 2.3% of these patients developed symptomatic gallstone disease and required cholecystectomy after an average of 12.4 mo.

Villegas et al[45] performed simultaneous cholecystectomy on 14% of patients after intraoperative diagnosis of gallstones or sludge with the aid of laparoscopic ultrasound. The global need for a subsequent cholecystectomy was 7%. Patients completing prophylactic ursodeoxycholic acid treatment had a significantly lower need of subsequent cholecystectomy.

In the series of open gastric bypass of Caruana et al[46] the diagnosis of gallstones was made by intraoperative palpation of the gallbladder. The authors did not report significant morbidity related to the addition of cholecystectomy. A subgroup of 125 patients that did not undergo simultaneous cholecystectomy was followed for at least 16 mo, requiring 8% of them to have a subsequent cholecystectomy for symptomatic gallstone disease.

Ahmed et al[47] retrospectively analyzed a series of 400 consecutive patients and found only significant differences in terms of operative times, which were 29 min longer for patients undergoing simultaneous elective cholecystectomy. No information about the incidence of symptomatic gallstone disease in the population without simultaneous elective cholecystectomy is given.

The group of the Universidad Católica de Chile reports a rate of simultaneous elective cholecystectomy of 10.9%[48]. The only significant differences were found for operative times, which were higher for the population undergoing simultaneous elective cholecystectomy. No information regarding the incidence of symptomatic gallstones in the population without simultaneous elective cholecystectomy was given.

Taylor et al[49] performed simultaneous cholecystectomy on 15% of patients. They reported the lowest need for subsequent cholecystectomy without the administration of prophylactic ursodeoxycholic acid, with only 3% of patients requiring it.

Tucker et al[50] performed simultaneous cholecystectomy on 7.2% of patients. A subgroup of patients was not submitted to this approach although they had gallstones present at the time of gastric bypass. The need for subsequent cholecystectomy in these patients was 17.6% whereas for patients without gallstones at the time of gastric bypass it was 6%.

A summary of these results is presented in Table Table11.


This consists of performing cholecystectomy only in the presence of both gallstones and symptoms, following the present guidelines for gallstone disease management[51,52]. The rationale behind this approach is to indicate cholecystectomy only for the patients requiring it and since most of the subsequent cholecystectomies are performed when a significant weight loss is achieved, the operation is done in a leaner and healthier patient.

Swartz et al[53] found an incidence of subsequent cholecystectomy of 14.7%, with a significant lower incidence for patients completing prophylactic ursodeoxycholic acid treatment. In Fuller and coworker’s experience, the need for subsequent cholecystectomy in patients completing prophylactic ursodeoxycholic acid treatment was 7.69%[54].

Ellner et al[55] and Portenier et al[56] did not administer prophylactic ursodeoxycholic acid treatment and found an incidence of subsequent cholecystectomy of 9% and 8.1%, respectively.

Papasavas et al[39] did an interesting study in which they retrospectively reviewed the records of 644 patients undergoing gastric bypass without simultaneous cholecystectomy. All of them received postoperative prophylactic ursodeoxycholic acid treatment. The need for a subsequent cholecystectomy in patients with gallstones present at the time of gastric bypass was 8.3%, which is similar to the incidence observed for patients without gallstones (6.9%) and to the incidence for patients without preoperative ultrasound screening (8.3%). After obtaining these results, this group no longer screens for gallstones preoperatively. Similarly, Patel et al[57] at the UCLA School of Medicine found an incidence of subsequent cholecystectomy without preoperative screening and without postoperative ursodeoxycholic acid administration of 6%. A subsequent analysis by the same group with a longer follow up showed an even lower rate of subsequent cholecystectomy of 4.9%[58].

In our experience at Cosme Argerich Hospital from Buenos Aires, the global need for cholecystectomy after gastric bypass, without prophylactic ursodeoxycholic acid treatment, was 9.84% (unpublished data). For patients with gallstones present at the time of surgery a subsequent cholecystectomy was needed in 5% and for patients without gallstones in 10.71% (P: not significant). Based on our own data, the natural history of patients with asymptomatic gallstones undergoing gastric bypass is very much like the natural history of asymptomatic gallstones in the general population[59-61].

A summary of these results is presented in Table Table11.


The preventive administration of ursodeoxycholic acid proved to be significantly better than placebo in preventing gallstone formation in a double blind, prospective and randomized study conducted by Sugerman et al[62]. A daily dose of 600 mg was associated with the lowest rate of gallstone formation and the lowest incidence of adverse events. Patients that developed gallstones showed a lower compliance rate. The effect of the 6 mo treatment seems to last for at least 1 year, since at that moment patients were reevaluated with ultrasonography and the incidence of gallstones was significantly less compared to the placebo arm. Unfortunately, there is no mention in the study regarding how many of those patients that developed gallstones were actually symptomatic and therefore required cholecystectomy, since the actual standard of care for non-obese patients indicates a cholecystectomy only when both symptoms and gallstones are present (SSAT NIH). A true benefit for ursodeoxycholic acid would be a lower rate of delayed cholecystectomy over the placebo group.

Wudel et al[63] compared, in a randomized double-blind fashion, a cohort of 60 patients without gallstones at the time of open gastric bypass and prescribed them a 6-mo course of ursodeoxycholic acid, ibuprofen or placebo. 71% of the patients subsequently developed gallstones and no benefit of the two therapies investigated could be demonstrated because of an extremely low compliance rate of 28%.

A recently published meta-analysis by Uy et al[64] concluded that ursodeoxycholic acid administration prevents gallstone formation after bariatric surgery, but no meta-analysis of symptomatic gallstones could be done, since only one paper addressed this topic and unfortunately did not include patients undergoing gastric bypass[65].


Prophylactic and selective management can be safely performed and the only significant difference with patients not submitted to concomitant cholecystectomy is mostly observed in operative times that are higher in those who do undergo cholecystectomy. Data obtained from conventional management studies, with or without ursodeoxycholic acid administration, show that most of the patients remain asymptomatic even when they develop gallstones and therefore do not require a subsequent cholecystectomy, so that the risks of performing a concomitant cholecystectomy might be unwarranted. Treatment with ursodeoxycholic acid prevents gallstone formation after gastric bypass but most of the studies conducted show a low compliance rate and do not mention the true benefit of the treatment, which would be a lower cholecystectomy rate.


Peer reviewers: Florencia Georgina Que, MD, Department of Surgery, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, United States; Masayuki Sho, MD, PhD, Professor, Department of Surgery, Nara Medical University, 840 Shijo-cho, Kashihara, Nara, 634-8522, Japan; Jai Dev Wig, MS, FRCS, Former Professor and Head, Department of General Surgery, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India

S- Editor Wang YR L- Editor O’Neill M E- Editor Zheng XM


1. Nakeeb A, Comuzzie AG, Martin L, Sonnenberg GE, Swartz-Basile D, Kissebah AH, Pitt HA. Gallstones: genetics versus environment. Ann Surg. 2002;235:842–849. [PubMed]
2. Sarin SK, Negi VS, Dewan R, Sasan S, Saraya A. High familial prevalence of gallstones in the first-degree relatives of gallstone patients. Hepatology. 1995;22:138–141. [PubMed]
3. Dittrick GW, Thompson JS, Campos D, Bremers D, Sudan D. Gallbladder pathology in morbid obesity. Obes Surg. 2005;15:238–242. [PubMed]
4. Erlinger S. Gallstones in obesity and weight loss. Eur J Gastroenterol Hepatol. 2000;12:1347–1352. [PubMed]
5. Liddle RA, Goldstein RB, Saxton J. Gallstone formation during weight-reduction dieting. Arch Intern Med. 1989;149:1750–1753. [PubMed]
6. Stampfer MJ, Maclure KM, Colditz GA, Manson JE, Willett WC. Risk of symptomatic gallstones in women with severe obesity. Am J Clin Nutr. 1992;55:652–658. [PubMed]
7. Everhart JE, Khare M, Hill M, Maurer KR. Prevalence and ethnic differences in gallbladder disease in the United States. Gastroenterology. 1999;117:632–639. [PubMed]
8. Maclure KM, Hayes KC, Colditz GA, Stampfer MJ, Speizer FE, Willett WC. Weight, diet, and the risk of symptomatic gallstones in middle-aged women. N Engl J Med. 1989;321:563–569. [PubMed]
9. Pauletzki J, Paumgartner G. Review article: defects in gall-bladder motor function--role in gallstone formation and recurrence. Aliment Pharmacol Ther. 2000;14 Suppl 2:32–34. [PubMed]
10. Weinsier RL, Ullmann DO. Gallstone formation and weight loss. Obes Res. 1993;1:51–56. [PubMed]
11. Everhart JE. Contributions of obesity and weight loss to gallstone disease. Ann Intern Med. 1993;119:1029–1035. [PubMed]
12. Festi D, Colecchia A, Larocca A, Villanova N, Mazzella G, Petroni ML, Romano F, Roda E. Review: low caloric intake and gall-bladder motor function. Aliment Pharmacol Ther. 2000;14 Suppl 2:51–53. [PubMed]
13. Kamrath RO, Plummer LJ, Sadur CN, Adler MA, Strader WJ, Young RL, Weinstein RL. Cholelithiasis in patients treated with a very-low-calorie diet. Am J Clin Nutr. 1992;56:255S–257S. [PubMed]
14. Yang HY, Peterson GM, Mraks JW, Roth MP, Schoenfield LJ. Risk factors for gallstone formation during rapid weight loss (Abstract) Gastroenterology. 1990;98:A266.
15. Gebhard RL, Prigge WF, Ansel HJ, Schlasner L, Ketover SR, Sande D, Holtmeier K, Peterson FJ. The role of gallbladder emptying in gallstone formation during diet-induced rapid weight loss. Hepatology. 1996;24:544–548. [PubMed]
16. Shiffman ML, Sugerman HJ, Kellum JM, Moore EW. Changes in gallbladder bile composition following gallstone formation and weight reduction. Gastroenterology. 1992;103:214–221. [PubMed]
17. Petroni ML. Review article: gall-bladder motor function in obesity. Aliment Pharmacol Ther. 2000;14 Suppl 2:48–50. [PubMed]
18. Shiffman ML, Sugerman HJ, Kellum JH, Brewer WH, Moore EW. Gallstones in patients with morbid obesity. Relationship to body weight, weight loss and gallbladder bile cholesterol solubility. Int J Obes Relat Metab Disord. 1993;17:153–158. [PubMed]
19. Dowling RH. Review: pathogenesis of gallstones. Aliment Pharmacol Ther. 2000;14 Suppl 2:39–47. [PubMed]
20. Pazzi P, Scagliarini R, Gamberini S, Pezzoli A. Review article: gall-bladder motor function in diabetes mellitus. Aliment Pharmacol Ther. 2000;14 Suppl 2:62–65. [PubMed]
21. De Santis A, Attili AF, Ginanni Corradini S, Scafato E, Cantagalli A, De Luca C, Pinto G, Lisi D, Capocaccia L. Gallstones and diabetes: a case-control study in a free-living population sample. Hepatology. 1997;25:787–790. [PubMed]
22. Dowling RH, Hussaini SH, Murphy GM, Besser GM, Wass JA. Gallstones during octreotide therapy. Metabolism. 1992;41:22–33. [PubMed]
23. Hussaini SH, Murphy GM, Kennedy C, Besser GM, Wass JA, Dowling RH. The role of bile composition and physical chemistry in the pathogenesis of octreotide-associated gallbladder stones. Gastroenterology. 1994;107:1503–1513. [PubMed]
24. Qvist N. Review article: gall-bladder motility after intestinal surgery. Aliment Pharmacol Ther. 2000;14 Suppl 2:35–38. [PubMed]
25. Fukagawa T, Katai H, Saka M, Morita S, Sano T, Sasako M. Gallstone formation after gastric cancer surgery. J Gastrointest Surg. 2009;13:886–889. [PubMed]
26. Al-Azzawi HH, Nakeeb A, Saxena R, Maluccio MA, Pitt HA. Cholecystosteatosis: an explanation for increased cholecystectomy rates. J Gastrointest Surg. 2007;11:835–842; discussion 842-843. [PubMed]
27. Schwesinger WH, Diehl AK. Changing indications for laparoscopic cholecystectomy. Stones without symptoms and symptoms without stones. Surg Clin North Am. 1996;76:493–504. [PubMed]
28. Bingener J, Richards ML, Schwesinger WH, Sirinek KR. Laparoscopic cholecystectomy for biliary dyskinesia: correlation of preoperative cholecystokinin cholescintigraphy results with postoperative outcome. Surg Endosc. 2004;18:802–806. [PubMed]
29. Ponsky TA, DeSagun R, Brody F. Surgical therapy for biliary dyskinesia: a meta-analysis and review of the literature. J Laparoendosc Adv Surg Tech A. 2005;15:439–442. [PubMed]
30. Cottam DR, Fisher B, Sridhar V, Atkinson J, Dallal R. The effect of stoma size on weight loss after laparoscopic gastric bypass surgery: results of a blinded randomized controlled trial. Obes Surg. 2009;19:13–17. [PubMed]
31. Choban PS, Flancbaum L. The effect of Roux limb lengths on outcome after Roux-en-Y gastric bypass: a prospective, randomized clinical trial. Obes Surg. 2002;12:540–545. [PubMed]
32. Nelson WK, Fatima J, Houghton SG, Thompson GB, Kendrick ML, Mai JL, Kennel KA, Sarr MG. The malabsorptive very, very long limb Roux-en-Y gastric bypass for super obesity: results in 257 patients. Surgery. 2006;140:517–522, discussion 522-523. [PubMed]
33. Patiño JF, Quintero GA. Asymptomatic cholelithiasis revisited. World J Surg. 1998;22:1119–1124. [PubMed]
34. Deitel M, Petrov I. Incidence of symptomatic gallstones after bariatric operations. Surg Gynecol Obstet. 1987;164:549–552. [PubMed]
35. Myers JA, Fischer GA, Sarker S, Shayani V. Gallbladder disease in patients undergoing laparoscopic adjustable gastric banding. Surg Obes Relat Dis. 2005;1:561–563. [PubMed]
36. Mason EE, Renquist KE. Gallbladder management in obesity surgery. Obes Surg. 2002;12:222–229. [PubMed]
37. Fobi M, Lee H, Igwe D, Felahy B, James E, Stanczyk M, Fobi N. Prophylactic cholecystectomy with gastric bypass operation: incidence of gallbladder disease. Obes Surg. 2002;12:350–353. [PubMed]
38. Hamad GG, Ikramuddin S, Gourash WF, Schauer PR. Elective cholecystectomy during laparoscopic Roux-en-Y gastric bypass: is it worth the wait? Obes Surg. 2003;13:76–81. [PubMed]
39. Papasavas PK, Gagné DJ, Ceppa FA, Caushaj PF. Routine gallbladder screening not necessary in patients undergoing laparoscopic Roux-en-Y gastric bypass. Surg Obes Relat Dis. 2006;2:41–46; discussion 46-47. [PubMed]
40. Amaral JF, Thompson WR. Gallbladder disease in the morbidly obese. Am J Surg. 1985;149:551–557. [PubMed]
41. Guadalajara H, Sanz Baro R, Pascual I, Blesa I, Rotundo GS, López JM, Corripio R, Vesperinas G, Sancho LG, Montes JA. Is prophylactic cholecystectomy useful in obese patients undergoing gastric bypass? Obes Surg. 2006;16:883–885. [PubMed]
42. Seinige UL, Sataloff DM, Lieber CP, DellaCroce JM, Sorouri ES. Gallbladder Disease in the Morbidly Obese Patient. Obes Surg. 1991;1:51–56. [PubMed]
43. Nougou A, Suter M. Almost routine prophylactic cholecystectomy during laparoscopic gastric bypass is safe. Obes Surg. 2008;18:535–539. [PubMed]
44. Liem RK, Niloff PH. Prophylactic cholecystectomy with open gastric bypass operation. Obes Surg. 2004;14:763–765. [PubMed]
45. Villegas L, Schneider B, Provost D, Chang C, Scott D, Sims T, Hill L, Hynan L, Jones D. Is routine cholecystectomy required during laparoscopic gastric bypass? Obes Surg. 2004;14:206–211. [PubMed]
46. Caruana JA, McCabe MN, Smith AD, Camara DS, Mercer MA, Gillespie JA. Incidence of symptomatic gallstones after gastric bypass: is prophylactic treatment really necessary? Surg Obes Relat Dis. 2005;1:564–567; discussion 567-568. [PubMed]
47. Ahmed AR, O'Malley W, Johnson J, Boss T. Cholecystectomy during laparoscopic gastric bypass has no effect on duration of hospital stay. Obes Surg. 2007;17:1075–1079. [PubMed]
48. Escalona A, Boza C, Muñoz R, Pérez G, Rayo S, Crovari F, Ibáñez L, Guzmán S. Routine preoperative ultrasonography and selective cholecystectomy in laparoscopic Roux-en-Y gastric bypass. Why not? Obes Surg. 2008;18:47–51. [PubMed]
49. Taylor J, Leitman IM, Horowitz M. Is routine cholecystectomy necessary at the time of Roux-en-Y gastric bypass? Obes Surg. 2006;16:759–761. [PubMed]
50. Tucker ON, Fajnwaks P, Szomstein S, Rosenthal RJ. Is concomitant cholecystectomy necessary in obese patients undergoing laparoscopic gastric bypass surgery? Surg Endosc. 2008;22:2450–2454. [PubMed]
51. Gallstones and laparoscopic cholecystectomy. NIH Consensus Development Panel on Gallstones and Laparoscopic Cholecystectomy. Surg Endosc. 1993;7:271–279. [PubMed]
52. Society for Surgery of the Alimentary Tract. SSAT patient care guidelines. Treatment of gallstone and gallbladder disease. J Gastrointest Surg. 2007;11:1222–1224. [PubMed]
53. Swartz DE, Felix EL. Elective cholecystectomy after Roux-en-Y gastric bypass: why should asymptomatic gallstones be treated differently in morbidly obese patients? Surg Obes Relat Dis. 2005;1:555–560. [PubMed]
54. Fuller W, Rasmussen JJ, Ghosh J, Ali MR. Is routine cholecystectomy indicated for asymptomatic cholelithiasis in patients undergoing gastric bypass? Obes Surg. 2007;17:747–751. [PubMed]
55. Ellner SJ, Myers TT, Piorkowski JR, Mavanur AA, Barba CA. Routine cholecystectomy is not mandatory during morbid obesity surgery. Surg Obes Relat Dis. 2007;3:456–460. [PubMed]
56. Portenier DD, Grant JP, Blackwood HS, Pryor A, McMahon RL, DeMaria E. Expectant management of the asymptomatic gallbladder at Roux-en-Y gastric bypass. Surg Obes Relat Dis. 2007;3:476–479. [PubMed]
57. Patel KR, White SC, Tejirian T, Han SH, Russell D, Vira D, Liao L, Patel KB, Gracia C, Haigh P, et al. Gallbladder management during laparoscopic Roux-en-Y gastric bypass surgery: routine preoperative screening for gallstones and postoperative prophylactic medical treatment are not necessary. Am Surg. 2006;72:857–861. [PubMed]
58. Patel JA, Patel NA, Piper GL, Smith DE 3rd, Malhotra G, Colella JJ. Perioperative management of cholelithiasis in patients presenting for laparoscopic Roux-en-Y gastric bypass: have we reached a consensus? Am Surg. 2009;75:470–476; discussion 476. [PubMed]
59. McSherry CK, Ferstenberg H, Calhoun WF, Lahman E, Virshup M. The natural history of diagnosed gallstone disease in symptomatic and asymptomatic patients. Ann Surg. 1985;202:59–63. [PubMed]
60. Friedman GD. Natural history of asymptomatic and symptomatic gallstones. Am J Surg. 1993;165:399–404. [PubMed]
61. Diehl AK. Epidemiology and natural history of gallstone disease. Gastroenterol Clin North Am. 1991;20:1–19. [PubMed]
62. Sugerman HJ, Brewer WH, Shiffman ML, Brolin RE, Fobi MA, Linner JH, MacDonald KG, MacGregor AM, Martin LF, Oram-Smith JC. A multicenter, placebo-controlled, randomized, double-blind, prospective trial of prophylactic ursodiol for the prevention of gallstone formation following gastric-bypass-induced rapid weight loss. Am J Surg. 1995;169:91–96; discussion 96-97. [PubMed]
63. Wudel LJ Jr, Wright JK, Debelak JP, Allos TM, Shyr Y, Chapman WC. Prevention of gallstone formation in morbidly obese patients undergoing rapid weight loss: results of a randomized controlled pilot study. J Surg Res. 2002;102:50–56. [PubMed]
64. Uy MC, Talingdan-Te MC, Espinosa WZ, Daez ML, Ong JP. Ursodeoxycholic acid in the prevention of gallstone formation after bariatric surgery: a meta-analysis. Obes Surg. 2008;18:1532–1538. [PubMed]
65. Miller K, Hell E, Lang B, Lengauer E. Gallstone formation prophylaxis after gastric restrictive procedures for weight loss: a randomized double-blind placebo-controlled trial. Ann Surg. 2003;238:697–702. [PubMed]

Articles from World Journal of Gastroenterology are provided here courtesy of Baishideng Publishing Group Inc