Calcium oxalate supersaturation increases early after Roux-en-Y gastric bypass

Higher Risk of Repeat Stone Surgery in Stone Formers With Concomitant Bowel Disease: Single-Center Long-Term Analysis

OBJECTIVE

To identify the need for repeat stone surgery in patients with and without bowel disease. Few studies have compared risks between different types of bowel disease and whether their need for repeat stone surgery differs.

METHODS

From our IRB-approved study, we identified patients with and without bowel disease. We categorized patients' bowel disease into 4 categories: inflammatory bowel disease (IBD), bypass procedures, bowel resection, and bowel disease not otherwise specified (eg, irritable bowel syndrome, celiac disease). Differences between patient demographics, stone disease, and recurrent stone events for patients with and without bowel disease were compared using univariate and multivariate survival analyses (SPSS 25).

RESULTS

Of all surgical stone patients (2011), 484 (24%) had some type of bowel disease. Compared to patients without bowel disease, patients with bowel disease presented with stones at an older age (62.2 ± 14.5 vs 58.4 ± 15.3 years; P <.001) and were more likely to be female (56 vs 46%; P <.001). Patients with bowel disease required more repeat stone surgery than those without bowel disease (31% vs 23%, P <.001). In multivariate analysis, patients with bypass and bowel resection were associated with more repeat surgery than patients without bowel disease (P <.001, P = .002, respectively). Patients with IBD and bowel disease not otherwise specified did not have higher risk for repeat surgery than patients without bowel disease.

CONCLUSION

Surgical stone patients with bowel disease, specifically those with prior bowel resection and bypass, had a higher risk of repeat stone surgery over time than stone formers without bowel disease.

DATA AVAILABILITY

The data sets generated and analyzed during the current study are available from the corresponding author on reasonable request.

Beneficial roles of gastrointestinal and urinary microbiomes in kidney stone prevention via their oxalate-degrading ability and beyond

Formation of calcium oxalate (CaOx) crystal, the most common composition in kidney stones, occurs following supersaturation of calcium and oxalate ions in the urine. In addition to endogenous source, another main source of calcium and oxalate ions is dietary intake. In the intestinal lumen, calcium can bind with oxalate to form precipitates to be eliminated with feces. High intake of oxalate-rich foods, inappropriate amount of daily calcium intake, defective intestinal transporters for oxalate secretion and absorption, and gastrointestinal (GI) malabsorption (i.e., from gastric bypass surgery) can enhance intestinal oxalate absorption, thereby increasing urinary oxalate level and risk of kidney stone disease (KSD). The GI microbiome rich with oxalate-degrading bacteria can reduce intestinal oxalate absorption and urinary oxalate level. In addition to the oxalate-degrading ability, the GI microbiome also affects expression of oxalate transporters and net intestinal oxalate transport, cholesterol level, and short-chain fatty acids (SCFAs) production, leading to lower KSD risk. Recent evidence also shows beneficial effects of urinary microbiome in KSD prevention. This review summarizes the current knowledge on the aforementioned aspects. Potential benefits of the GI and urinary microbiomes as probiotics for KSD prevention are emphasized. Finally, challenges and future perspectives of probiotic treatment in KSD are discussed.

Dietary advice for patients with bowel-related conditions and malabsorption

PURPOSE

To explain the pathophysiology of kidney stone formation and appropriate dietary recommendations in inflammatory bowel diseases (IBD) such as ulcerative colitis (UC) and Crohn's disease (CD) and after bariatric surgery, focusing on the current literature.

METHODS

A narrative review methodology was performed. A literature search was conducted using PubMed, MEDLINE, and Google Scholar. Studies on the relationship between IBD or bariatric surgery and the risk of kidney stone formation were included.

RESULTS

Dietary composition has a critical role in urinary stone formation. Nutritional factors such as fluid intake, dietary protein, carbohydrates, oxalate, and calcium contribute to the risk of stone formation. Bowel-related malabsorptive conditions (IBD, after bariatric surgery, etc.) are associated with an increased risk of kidney stone formation due to metabolic and physiological changes such as hyperoxaluria, hypocitraturia, and decreased fluid intake or absorption. While the risk is lower in restrictive bariatric surgeries, the risk of kidney stone formation increases, especially after malabsorptive procedures. Dietary recommendations for these patients could profit alleviate urinary changes and reduce the risk of kidney stones.

CONCLUSION

Bowel-related malabsorptive conditions such as IBD and bariatric surgery are associated with an increased risk of kidney stones. Appropriate dietary recommendations can improve urinary metabolic changes and reduce kidney stone formation and the possibility of stone-related surgery.

Effect of preoperative metabolic profiling to reduce the risk of kidney stones after bariatric surgery in patients with a history of stone formation

BACKGROUND

Roux-en-Y gastric bypass (RYGB) is associated with an increased risk of kidney stone formation. This is not observed after sleeve gastrectomy (SG).

OBJECTIVES

Aim of this study was to assess whether preoperative metabolic profiling is helpful in selecting the most optimal bariatric procedure for patients with a kidney stone history.

SETTING

General hospital, the Netherlands.

METHODS

Patients with a kidney stone history and in the run up to bariatric surgery were screened with non-contrast abdominal computed tomography (CT), serum profiling, and 24-hour urine analysis. Those with stones on radiologic imaging and/or high preoperative urinary oxalate were advised to undergo SG instead of RYGB. Pre- and postoperative urine and serum profile differences between both groups were evaluated retrospectively.

RESULTS

Postoperatively, RYGB (N = 28, M:F = 8:20) was associated with a 23.5% reduction in urinary volume, a 85% increase in urinary oxalate excretion with a 230% increase in calcium oxalate (CaOx) supersaturation and a 62% decrease in urinary citrate. Although SG (N = 30, M:F = 12:18) was also associated with a reduction in urinary volume, it had no adverse effects on urinary oxalate and citrate excretion, nor on calcium oxalate supersaturation (CaOx-SS). Both RYGB and SG showed favorable effects on postoperative sodium, calcium, uric acid, and phosphate excretion.

CONCLUSIONS

This study indicates that preoperative metabolic profiling is important to select the optimal bariatric procedure in patients with an a priori increased risk of kidney stone development. These patients should be strongly encouraged to undergo SG instead of RYGB to prevent progressive or recurrent kidney stone disease.

Urolithiasis and sleeve gastrectomy: a prospective assessment of urinary biochemical variables

INTRODUCTION

to evaluate urinary biochemical alterations related to urolithogenesis processes after sleeve gastrectomy (SG).

MATERIALS AND METHODS

: prospective study with 32 individuals without previous diagnosis of urolithiasis who underwent SG. A 24-h urine test was collected seven days prior to surgery and at 6-month follow-up. The studied variables were urine volume, urinary pH, oxalate, calcium, citrate, and magnesium and calcium oxalate super saturation (CaOx SS).

RESULTS

patients were mainly women (81.2%), with mean age of 40.6 years. Mean pre- and postoperative BMI were 47.1 ± 8.3 Kg/m2 and 35.5 ± 6.1 Kg/m2, respectively (p<0.001). Urine volume was significantly lower at the postoperative evaluation in absolute values (2,242.50 ± 798.26 mL x 1,240.94 ± 352.39 mL, p<0.001) and adjusted to body weight (18.58 ± 6.92 mL/kg x 13.92 ± 4.65 mL/kg, p<0.001). CaOx SS increased significantly after SG (0.11 ± 0.10 x 0.24 ± 0.18, p<0.001). Moreover, uric acid levels were significantly lower at the postoperative evaluation (482.34 ± 195.80 mg x 434.75 ± 158.38 mg, p=0.027). Urinary pH, oxalate, calcium, citrate, and magnesium did not present significant variations between the pre- and postoperative periods.

CONCLUSION

SG may lead to important alterations in the urinary profile. However, it occurs in a much milder way than that of RYGB.

Bariatric Surgery in Patients with a History of Nephrolithiasis: 24-h Urine Profiles and Radiographic Changes After Roux-en-Y Gastric Bypass Versus Sleeve Gastrectomy

BACKGROUND

To evaluate the differences in 24-h urine profiles, radiographic imaging, and stone events post-Roux-en-Y gastric bypass versus sleeve gastrectomy in patients with a history of nephrolithiasis.

METHODS

A retrospective review was conducted on 102 patients with a history of nephrolithiasis who then underwent bariatric surgery at our tertiary academic center. Computed tomography imaging and 24-h urine profile values were performed pre-operatively and at 1-year follow-up.

RESULTS

A total of 60 patients underwent Roux-en-Y gastric bypass and 42 had sleeve gastrectomy. The Roux-en-Y gastric bypass group had significant increases in oxalate and decreases in citrate (p = 0.009 and 0.003, respectively), while the sleeve gastrectomy group had decreases in oxalate and stable citrate (p = 0.013 and 0.906, respectively). Roux-en-Y gastric bypass was the only significant predictor of post-operative hyperoxaluria (OR 7.1 [95% CI 2.3-21.3], p = 0.001). Radiographically, 38.3% of the Roux-en-Y gastric bypass group and 26.2% of the sleeve gastrectomy group had an increase in stone burden, and post-operative stone procedure rate was 10.0% and 7.1%, respectively.

CONCLUSIONS

At 1-year post-bariatric surgery, patients who underwent Roux-en-Y gastric bypass had exacerbated lithogenic urinary profiles, while those in sleeve gastrectomy patients improved. Although not statistically significant, stone burden increase and stone procedure rate were higher post-Roux-en-Y gastric bypass and will likely worsen at a longer follow-up due to the group's lithogenic 24-h urine profiles. These findings support pre-bariatric counseling and urinary monitoring in patients with a history of kidney stones who undergo RYGB, with a multi-disciplinary approach between urologists and general surgeons.

Risk Factors for Kidney Stone Formation following Bariatric Surgery

Kidney stones are painful, common, and increasing in incidence. Obesity and bariatric surgery rates are also on the rise in the United States. Although bariatric surgery is associated with improvements in metabolic outcomes, malabsorptive bariatric surgery procedures are also associated with increased risk of kidney stones. Restrictive bariatric surgeries have not been associated with kidney-stone risk. Higher risk of kidney stones after malabsorptive procedures is associated with postsurgical changes in urine composition, including high urine oxalate, low urine citrate, and low urine volume. Certain dietary recommendations after surgery may help mitigate these urine changes and reduce risk of kidney stones. Understanding risk of kidney stones after surgery is essential to improving patient outcomes after bariatric surgery.

Subsequent urinary stone events are predicted by the magnitude of urinary oxalate excretion in enteric hyperoxaluria

 

Data directly demonstrating the relationship between urinary oxalate (UOx) excretion and stone events in those with enteric hyperoxaluria (EH) are limited. Therefore, we assessed the relationship between UOx excretion and risk of kidney stone events in a retrospective population-based EH cohort. In all, 297 patients from Olmsted County, Minnesota were identified with EH based upon having a 24-h UOx ≥40 mg/24 h preceded by a diagnosis or procedure associated with malabsorption. Diagnostic codes and urologic procedures consistent with kidney stones during follow-up after baseline UOx were considered a new stone event. Logistic regression and accelerated failure time modeling were performed as a function of UOx excretion to predict the probability of new stone event and the annual rate of stone events, respectively, with adjustment for urine calcium and citrate. Mean ± standard deviation age was 51.4 ± 11.4 years and 68% were female. Median (interquartile range) UOx was 55.4 (46.6-73.0) mg/24 h and 81 patients had one or more stone event during a median follow-up time of 4.9 (2.8-7.8) years. Higher UOx was associated with a higher probability of developing a stone event (P < 0.01) and predicted an increased annual risk of kidney stones (P = 0.001). Estimates derived from these analyses suggest that a 20% decrease in UOx is associated with 25% reduction in the annual odds of a future stone event. Thus, these data demonstrate an association between baseline UOx and stone events in EH patients and highlight the potential benefit of strategies to reduce UOx in this patient group.

BACKGROUND

Data directly demonstrating the relationship between urinary oxalate (UOx) excretion and stone events in those with enteric hyperoxaluria (EH) are limited.

METHODS

We assessed the relationship between UOx excretion and risk of kidney stone events in a retrospective population-based EH cohort. In all, 297 patients from Olmsted County, Minnesota were identified with EH based upon having a 24-h UOx ≥40 mg/24 h preceded by a diagnosis or procedure associated with malabsorption. Diagnostic codes and urologic procedures consistent with kidney stones during follow-up after baseline UOx were considered a new stone event. Logistic regression and accelerated failure time modeling were performed as a function of UOx excretion to predict the probability of new stone event and the annual rate of stone events, respectively, with adjustment for urine calcium and citrate.

RESULTS

Mean ± SD age was 51.4 ± 11.4 years and 68% were female. Median (interquartile range) UOx was 55.4 (46.6-73.0) mg/24 h and 81 patients had ≥1 stone event during a median follow-up time of 4.9 (2.8-7.8) years. Higher UOx was associated with a higher probability of developing a stone event (P < 0.01) and predicted an increased annual risk of kidney stones (P = 0.001). Estimates derived from these analyses suggest that a 20% decrease in UOx is associated with 25% reduction in the annual odds of a future stone event.

CONCLUSIONS

These data demonstrate an association between baseline UOx and stone events in EH patients and highlight the potential benefit of strategies to reduce UOx in this patient group.

Common and Rare Complications of Bariatric Surgery

As the prevalence of obesity has increased, bariatric surgery has become more common because of its proven efficacy at promoting weight loss and improving weight-related medical comorbidities. Although generally successful, bariatric surgery may also lead to complications and negatively affect health. This article highlights some common and rare complications of bariatric surgery. Specifically, it discusses the risk of nutrient deficiencies (which is influenced by surgery type) and their downstream effects, including ill-effects on bone health. Rarer complications, such as postbypass hypoglycemia and alcohol use disorder, are also discussed.

Enteric hyperoxaluria: role of microbiota and antibiotics

PURPOSE OF REVIEW

Enteric hyperoxaluria is commonly observed in malabsorptive conditions including Roux en Y gastric bypass (RYGB) and inflammatory bowel diseases (IBD). Its incidence is increasing secondary to an increased prevalence of both disorders. In this review, we summarize the evidence linking the gut microbiota to the risk of enteric hyperoxaluria.

RECENT FINDINGS

In enteric hyperoxaluria, fat malabsorption leads to increased binding of calcium to free fatty acids resulting in more soluble oxalate in the intestinal lumen. Bile acids and free fatty acids in the lumen also cause increased gut permeability allowing more passive absorption of oxalate. In recent years, there is more interest in the role of the gut microbiota in modulating urinary oxalate excretion in enteric hyperoxaluria, stemming from our knowledge that microbiota in the intestines can degrade oxalate. Oxalobacter formigenes reduced urinary oxalate in animal models of RYGB. The contribution of other oxalate-degrading organisms and the microbiota community to the pathophysiology of enteric hyperoxaluria are also currently under investigation.

SUMMARY

Gut microbiota might play a role in modulating the risk of enteric hyperoxaluria through oxalate degradation and bile acid metabolism. O. formigenes is a promising therapeutic target in this population; however, further studies in humans are needed to test its effectiveness.

Nephrolithiasis after bariatric surgery: A comparison of laparoscopic Roux-en-Y gastric bypass and sleeve gastrectomy

INTRODUCTION

Laparoscopic Roux-en-Y gastric bypass (LRYGB) is known to increase risk for calcium oxalate nephrolithiasis due to hyperoxaluria; however, nephrolithiasis rates after laparoscopic sleeve gastrectomy (LSG) are not well described. Our objective was to determine the rate of nephrolithiasis after LRYGB versus LSG.

METHODS

The electronic medical records of patients who underwent LRYGB or LSG between 2001 and 2017 were retrospectively reviewed.

RESULTS

1,802 patients were included. Postoperative nephrolithiasis was observed in 133 (7.4%) patients, overall, and 8.12% of LRYGB (122/1503) vs. 3.68% of LSG (11/299) patients (P < 0.001). Mean time to stone formation was 2.97 ± 2.96 years. Patients with a history of UTI (OR = 2.12, 95%CI 1.41-3.18; P < 0.001) or nephrolithiasis (OR = 8.81, 95%CI 4.93-15.72; P < 0.001) were more likely to have postoperative nephrolithiasis.

CONCLUSION

The overall incidence of symptomatic nephrolithiasis after bariatric surgery was 7.4%. Patients who underwent LRYGB had a higher incidence of nephrolithiasis versus LSG. Patients with a history of stones had the highest risk of postoperative nephrolithiasis.

Review of post bariatric surgery effects on common genitourinary physiology

Background: Obesity is a worldwide challenging health problem. Weight loss through medical management of obesity has not always been successful, thus, giving rise to the need for surgical intervention. Bariatric surgery has been shown to be helpful for morbidly obese patients. However, studies have also shown the effect of surgery on stone formation, fertility and erectile function. This review summarizes the main findings of several studies that analyze stone formation and fertility in men as well as erectile function post bariatric surgery. The underlying pathophysiologic alterations post bariatric surgery include increased absorption of oxalate leading to hyperoxaluria, hypocitraturia and increased urinary calcium oxalate supersaturation. Contradicting data exist on the effect of bariatric surgery on fertility and erectile function. Further studies are needed to analyze the mechanisms.

Kidney Stones After Bariatric Surgery: Risk Assessment and Mitigation

Obesity is rampant across the spectrum of age, gender, and race in the Unites States. Paralleling this epidemic, kidney stone prevalence is also rising, affecting nearly 1 in 11 individuals. Bariatric surgical procedures, such as Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), are the most effective weight loss options for morbidly obese or severely obese individuals with comorbidities. A number of studies have linked kidney stone development to bariatric surgical history, particularly RYGB, which portends up to a threefold increase in calcium oxalate stone risk compared with age-matched, obese controls. Stone development after malabsorptive (RYGB) and restrictive (SG) bariatric procedures are driven primarily by alterations in 24-h urine profiles, such as increased urinary oxalate, decreased urine volume, and reduced urinary citrate levels-all of which have been linked to increased kidney stone risk. What clinical recommendations, if any, can be given to reduce kidney stone risk in bariatric kidney stone patients? This review provides not only updated stone incidence and 24-h urine data in this population, but also reassurance-the metabolic alterations that result from bariatric surgery can be successfully mitigated by increased provider awareness, patient education, and a combination of dietary and pharmacological adjustments.

Nephrolithiasis after bariatric surgery: A review of pathophysiologic mechanisms and procedural risk

Obesity alone is a known risk factor for nephrolithiasis, and bariatric surgery has been linked to a higher incidence of post-operative new-onset nephrolithiasis. The mean interval from bariatric surgery to diagnosis of nephrolithiasis, ranges from 1.5 to 3.6 years. The stone risk is greatest for purely malabsorptive procedures, intermediate for Roux-en-Y gastric bypass and lowest for purely restrictive procedures (laparoscopic adjustable gastric banding, laparoscopic sleeve gastrectomy) where it approaches or is reduced below that of non-operative obese controls. A history of nephrolithiasis and increasing age at the time of surgery are both associated with an increased risk of new stone formation post-operatively. The underlying pathophysiologic changes following bariatric surgery include increased colonic absorption of oxalate leading to hyperoxaluria, hypocitraturia and increased urinary calcium oxalate supersaturation, which predispose to stone formation. The majority of incident stones are medically managed, with some requiring interventions in the form of lithotripsy or ureteroscopy.

Animal models of urinary stone disease

The etiology of stone disease remains unknown despite the major technological advances in the treatment of urinary calculi. Clinically, urologists have relied on 24-h urine collections for the last 30-40 years to help direct medical therapy in hopes of reducing stone recurrence; yet little progress has been made in preventing stone disease. As such, there is an urgent need to develop reliable animal models to study the pathogenesis of stone formation and to assess novel interventions. A variety of vertebrate and invertebrate models have been used to help understand stone pathogenesis. Genetic knockout and exogenous induction models are described. Surrogates for an endpoint of stone formation have been urinary crystals on histologic examination and/or urinalyses. Other models are able to actually develop true stones. It is through these animal models that real breakthroughs in the management of urinary stone disease will become a reality.

Reversal of Gastric Bypass Resolves Hyperoxaluria and Improves Oxalate Nephropathy Secondary to Roux-en-Y Gastric Bypass

Hyperoxaluria after Roux-en-Y gastric bypass (RYGB) increases the risk for kidney injury. Medical therapies for hyperoxaluria have limited efficacy. A 65-year-old female was evaluated for acute kidney injury [AKI, serum creatinine (Cr) 2.1 mg/dl, baseline Cr 1.0 mg/dl]. She did not have any urinary or gastrointestinal symptoms or exposure to nephrotoxic agents. Sixteen months prior to this evaluation, she underwent RYGB for morbid obesity. Her examination was unremarkable for hypertension or edema and there was no protein or blood on urine dipstick. Kidney biopsy revealed acute tubulointerstitial nephritis with oxalate crystals in tubules. The concurrent finding of severe hyperoxaluria (urine oxalate 150 mg/day) confirmed the diagnosis of oxalate nephropathy. Despite medical management of hyperoxaluria, her AKI worsened. Laparoscopic reversal of RYGB was performed and within 1 month, her hyperoxaluria resolved (urine oxalate 20 mg/day) and AKI improved (Cr 1.7 mg/dl). Surgical reversal of RYGB may be considered in patients with oxalate nephropathy at high risk of progression who fail medical therapy. Physicians need to be aware of the possibility of oxalate nephropathy after RYGB and promptly treat the hyperoxaluria to halt further kidney damage.

Risk of nephrolithiasis, hyperoxaluria, and calcium oxalate supersaturation increased after Roux-en-Y gastric bypass surgery: a systematic review and meta-analysis

BACKGROUND

Earlier publications have shown renal stone complications after bariatric surgery. Multiple reports have also linked metabolic changes that alter the urinary chemistry profiles, especially hyperoxaluria, after bariatric surgery. However, evidence on change of other urine chemistry studies and type of bariatric surgery and risk of stone has been inconclusive so far.

OBJECTIVES

To explore the association between bariatric surgery and postoperative urinary chemistry change and risk of stone formation SETTING: A systematic review and meta-analysis.

METHODS

We comprehensively searched the databases of MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) from their dates of inception to January 2016. The inclusion criteria were published studies of association between bariatric surgery and postoperative renal stone formation or urine chemistry profiles. We used random-effects model meta-analysis and calculated the pooled risk of renal stone and difference in 24-hour urine chemistry profiles.

RESULTS

Twelve observational studies were included in the meta-analysis. There was significantly higher risk of stone formation after Roux-en-Y gastric bypass surgery with pooled relative risk = 1.79 (95% CI: 1.54-2.10). In the analysis of urine chemistry profiles, there was significantly higher calcium oxalate supersaturation, lower citrate, and lower volume postoperatively compared with preoperatively. There was also higher urine oxalate in patients who had bariatric surgery compared with nonsurgery controls.

CONCLUSIONS

Roux-en-Y gastric bypass surgery is associated with higher risk of renal stone and increased urine oxalate and calcium oxalate supersaturation.

Oxalate nephropathy in systemic sclerosis: Case series and review of the literature

OBJECTIVE

To increase awareness of oxalate nephropathy as a cause of acute kidney injury (AKI) among systemic sclerosis patients with small intestinal dysmotility and malabsorption, and to prompt consideration of dietary modification and early treatment of predisposing causes of oxalate nephropathy in this population.

METHODS

Two cases of biopsy-proven oxalate nephropathy were identified among systemic sclerosis patients in the course of direct clinical care. Subsequently, a retrospective search of the Johns Hopkins Pathology databases identified a third patient with systemic sclerosis who developed oxalate nephropathy.

RESULTS

Among the three patients with qualifying biopsies, all three had systemic sclerosis with lower gastrointestinal involvement. All three presented with diarrhea, malabsorption, and AKI. In two of the three patients, diarrhea was present for at least 2 years before the development of AKI; in the third, incidental oxalate nephropathy was noted 3 years before she developed AKI and extensive oxalate nephropathy in the setting of a prolonged mycobacterium avium-intracellulare enteritis. In the first case, oxalate crystals were present by urinalysis months before diagnosis by biopsy; in the second, hyperoxaluria was diagnosed by urine collection immediately after; and in the third, oxalate crystals had been noted incidentally on post-transplant renal biopsy 3 years before the development of fulminant oxalate nephropathy. All three patients died within a year after diagnosis.

CONCLUSIONS

Patients with systemic sclerosis and bowel dysmotility associated with chronic diarrhea and malabsorption may be at risk for an associated oxalate nephropathy. Regular screening of systemic sclerosis patients with small bowel malabsorption syndromes through routine urinalysis or 24-h urine oxalate collection, should be considered. Further studies defining the prevalence of this complication in systemic sclerosis, the benefit of dietary modification on hyperoxaluria, the effect of treating small intestinal bowel overgrowth with antibiotics, and the effectiveness of probiotics, calcium supplements, or magnesium supplements to prevent hyperoxaluria-associated renal disease in these patients, are warranted.

Enteric hyperoxaluria: an important cause of end-stage kidney disease

Hyperoxaluria is a frequent complication of inflammatory bowel diseases, ileal resection and Roux-en-Y gastric bypass and is well-known to cause nephrolithiasis and nephrocalcinosis. The associated prevalence of chronic kidney disease and end-stage kidney disease (ESKD) is less clear but may be more consequential than recognized. In this review, we highlight three cases of ESKD due to enteric hyperoxaluria following small bowel resections. We review current information on the pathophysiology, complications and treatment of this complex disease.