Letter: bile acid malabsorption - what is the prevalence in patients with chronic diarrhoea?

Variation of enterohepatic circulation observed with 75SeHCAT images in the first three hours. Scintigraphic patterns and analysis of their association with the diagnosis of bile acid malabsorption

OBJETIVE

To evaluate the enterohepatic circulation of 75-Selenium turoselecolic acid (⁷⁵Se-SeHCAT) during the first 3 h and its correlation with the abdominal retention at the 7th day (AR₇), as contribution to the clinical study of biliar acid malabsorption (BAM).

MATERIALS AND METHODS

38 patients with chronic diarrhea were retrospectively studied. Acquisition protocol included static abdominal images at 1st, 2nd and 3rd hour and the 7th day after oral administration of the radiopharmaceutical. Images of 1-3 h determined 5 patterns of enterohepatic circulation that, due to their location, were characterized as: 1) gallbladder 2-3 h, 2) gallbladder 3 h, 3) gallbladder-abdomen 2-3 h, 4) abdomen, 5) upper left abdomen. The association of these patterns with the AR₇ (Fisher, STATA) were investigated. Patients were classified as Non BAM (AR₇ > 15%), mild-BAM (AR₇ 15-10%), moderate-BAM (AR₇ 10-5%) or severe-BAM (AR₇ < 5%).

RESULTS

19 patients had an AR₇ diagnostic of BAM (7 mild-BAM, 5 moderate-BAM, 7 severe-BAM). The pattern "gallbladder at 2-3 h" was statistically associated with Non BAM (p 0,008), while "gallbladder-abdomen at 2-3 h" was correlated with having BAM (p 0,029).

CONCLUSION

Variations detected at the abdominal level in images during the first 3 h were associated with changes in intestinal absorption and the incorporation of the radiopharmaceutical into the pool of bile acids, so visual interpretation of the images at 2nd and 3rd hour could be useful in the final assessment of the study.

Variation of enterohepatic circulation through the image with 75SeHCAT in the first 3 hours. Scintigraphic patterns and análisis of its association with the diagnosis of bile acid malabsorption

OBJETIVE

To evaluate the enterohepatic circulation of 75-Selenium turoselecolic acid (75Se-SeHCAT) during the first 3 hours and its correlation with the abdominal retention at the 7th day (AR7), as contribution to the clinical study of biliar acid malabsorption (BAM).

MATERIALS AND METHODS

38 patients with chronic diarrhea were retrospectively studied. Acquisition protocol included static abdominal images at 1st, 2nd and 3rd hour and the 7th day after oral administration of the radiopharmaceutical. Images of 1 to 3 hours determined 5 patterns of enterohepatic circulation that, due to their location, were characterized as: 1) gallbladder 2-3 hours, 2) gallbladder 3 hours, 3) gallbladder-abdomen 2-3 hours, 4) abdomen, 5) upper left abdomen. The association of these patterns with the AR7 (Fisher, STATA) were investigated. Patients were classified as Non BAM (AR7>15%), mild-BAM (AR7: 15-10%), moderate-BAM (AR7: 10-5%) or severe-BAM (AR7<5%).

RESULTS

19 patients had an AR7 diagnostic of BAM (7 mild-BAM, 5 moderate-BAM, 7 severe-BAM). The pattern "gallbladder at 2-3 hours" was statistically associated with Non BAM (p 0,008), while "gallbladder-abdomen at 2-3 hours" was correlated with having BAM (p 0,029).

CONCLUSION

Variations detected at the abdominal level in images during the first 3 hours were associated with changes in intestinal absorption and the incorporation of the radiopharmaceutical into the pool of bile acids, so visual interpretation of the images at 2nd and 3rd hour could be useful in the final assessment of the study.

Prevalence and clinical features of bile acid diarrhea in patients with chronic diarrhea

OBJECTIVE

Bile acid diarrhea is a form of chronic diarrhea caused by excessive bile reaching the colon. Conditions involving the terminal ileum and cholecystectomy are predisposing factors but an idiopathic form of bile acid diarrhea has also been described. In this study we aimed to evaluate the prevalence of bile acid diarrhea in patients consecutively evaluated for chronic diarrhea in an Outpatient Gastroenterology Clinic.

METHODS

Medical records of all patients admitted for chronic diarrhea (>4 weeks) between June 2018 and April 2019 were retrospectively reviewed. Bile acid diarrhea was suspected in patients with ileal disease, cholecystectomy or post-prandial diarrhea. Patients' age at diagnosis, sex, presenting symptoms, results of main test and examinations, final diagnoses and date of last follow-up visit were also collected. Exclusion of chronic diarrhea of other causes and a 6-month clinical improvement with cholestyramine treatment confirmed the diagnosis of bile acid diarrhea.

RESULTS

In total, 139 patients aged 46 ± 20 years (76 women and 63 men) were included. Diarrhea due to an organic cause was diagnosed in 16 patients. A clinical response to cholestyramine persisting for more than 6 months led to a diagnosis of bile acid diarrhea in 39 (aged 52 ± 19 years) out of the remaining 123 patients with functional forms of diarrhea. Therefore, the prevalence of bile acid diarrhea was 28.1% (95% confidence interval 19.9%-38.4%) in patients with chronic diarrhea.

CONCLUSIONS

Bile acid diarrhea is a very common, yet under-recognized cause of chronic functional diarrhea. A therapeutic trial of cholestyramine is a valid diagnostic strategy.

75SeHCAT scan in bile acid malabsorption in chronic diarrhoea

Chronic diarrhoea is a common entity in daily clinical practice and it leads to a loss in these patients quality of life. It may be the main symptom of multiple ethiologies including bile acid malabsorption (BAM) which has a comparable prevalence to celiac disease. The BAM results from imbalances in the homeostasis of bile acids in the enterohepatic circulation. It can be a consequence of ileal disease or ileal dysfunction (BAM type i), it can be considered idiopathic or primary (BAM type ii) or associated with other gastrointestinal entities (BAM type iii). Among the different diagnostic methods available, ⁷⁵SeHCAT study is the primary current method due to its sensitivity, specificity, safety and low cost. The main disadvantage is that it's not available in all countries, so other diagnostic methods have appeared, such as serum measurement of FGF19 and C4, however they are significantly more complex and costly. The first-line treatment of bile acid diarrhoea is bile acid sequestrant, such as cholestyramine, which can be difficult to administer due to its poor tolerability and gastrointestinal side effects. These are less prominent with newer agents such as colesevelam. In summary, the BAM is a common entity underdiagnosed and undertreated, so it is essential to establish a diagnosis algorithm of chronic diarrhoea in which the ⁷⁵SeHCAT study would be first or second line in the differential diagnosis of these patients.

High Prevalence of Idiopathic Bile Acid Diarrhea Among Patients With Diarrhea-Predominant Irritable Bowel Syndrome Based on Rome III Criteria

BACKGROUND & AIMS

Some studies have found that patients with idiopathic bile acid diarrhea (BAD) present with symptoms of diarrhea-predominant irritable bowel syndrome (D-IBS). However, these studies either were retrospective, did not define D-IBS according to current criteria, or included patients with chronic functional diarrhea. We performed a prospective study of the prevalence of idiopathic BAD in consecutive patients fulfilling the Rome III criteria for D-IBS.

METHODS

We analyzed data from 118 consecutive adult patients who fulfilled the Rome III criteria for D-IBS (mean age, 41.7 y; 72.9% female), seen at 2 gastroenterology clinics in the United Kingdom. We excluded patients with risk factors for BAD (previous history of cholecystectomy, terminal ileal Crohn's disease, terminal ileal resection or right hemicolectomy, pelvic or abdominal radiotherapy, celiac disease, or microscopic colitis). Participants completed questionnaires at baseline (on demographics, hospital anxiety, somatization, and depression, as well as the patient health questionnaire-12 and the Short Form-36), and then received the (75)selenium homocholic acid taurine retention test. Retention of (75)selenium homocholic acid taurine 7 days after administration was used to identify patients with idiopathic BAD (mild BAD, 10%-14.9%; moderate BAD, 5.1%-9.9%; and severe BAD, ≤5%).

RESULTS

Twenty-eight patients were found to have BAD (23.7% of total), with similar percentages at each study site (25.3% and 20%; P = .54). Eight patients had mild BAD (28.6%), 8 patients had moderate BAD (28.6%), and 12 patients had severe BAD (42.8%). There was no statistical difference in age, sex, depression, patient health questionnaire-12 responses, or SF-36 scores between individuals with vs without BAD. However, patients with BAD had a higher mean body mass index than patients without BAD (31.6 vs 26.4; P = .003). Physical activity (based on the Short Form-36) was significantly lower in subjects with moderate (43.8) or severe BAD (41.7), compared with patients with mild BAD (87.5) (P = .046).

CONCLUSIONS

Almost 25% of patients presenting with D-IBS have idiopathic BAD; most cases are moderate to severe. Guidelines should advocate testing to exclude BAD before patients are diagnosed with D-IBS.

Quantifying bile acid malabsorption helps predict response and tailor sequestrant therapy

Although recognised as a cause of chronic diarrhoea for over forty years, diagnostic tests and treatments for bile acid malabsorption (BAM) remain controversial. Recent National Institute for Health and Care Excellence (NICE) guidelines highlighted the lack of evidence in the field, and called for further research. This retrospective study explores the BAM subtype and severity, the use and response to bile acid sequestrants (BAS) and the prevalence of abnormal colonic histology. 264 selenium-75-labelled homocholic acid conjugated taurine (SeHCAT)-tested patient records were reviewed and the severity and subtype of BAM, presence of colonic histopathology and response to BAS were recorded. 53% of patients tested had BAM, with type-2 BAM in 45% of patients with presumed irritable bowel syndrome. Colonic histological abnormalities were similar overall between patients with (29%) or without (23%) BAM (p = 0.46) and between BAM subtypes, with no significant presence of inflammatory changes. 63% of patients with BAM had a successful BAS response which showed a trend to decreased response with reduced severity. Colestyramine was unsuccessful in 44% (38/87) and 45% of these (17/38) were related to medication intolerance, despite a positive SeHCAT. 47% (7/15) of colestyramine failures had a successful colesevelam response. No patient reported colesevelam intolerance. Quantifying severity of BAM appears to be useful in predicting BAS response. Colesevelam was better tolerated than colestyramine and showed some efficacy in colestyramine failures. Colestyramine failure should not be used to exclude BAM. Colonic histology is of no relevance.