Bile acid malabsorption caused by gastrointestinal motility dysfunction? An investigation of gastrointestinal disturbances in familial amyloidosis with polyneuropathy.

Gastrointestinal dysfunction due to autonomous neuropathy is a complication described in various diseases such as diabetes mellitus, multiple sclerosis, and familial amyloidosis with polyneuropathy. We present the results of a prospective investigation of bile acid malabsorption in 17 patients with familial amyloidosis by means of 75Se-labelled homocholic-tauro acid (SeHCAT). The diagnosis was in all cases verified by the DNA test for mutation of transthyretin in position 30. Small-intestinal biopsy specimens were examined for deposits of amyloid, and the presence of gastric retention was evaluated by gastroscopy. In addition, the patients were investigated for bacterial overgrowth by means of the bile acid breath test (BABT). A high frequency of abnormal BABT results (44%) was encountered. However, 65% also had abnormal low SeHCAT values, indicating bile acid malabsorption. Only two patients had abnormal BABT and normal SeHCAT results, indicating bacterial contamination of the small intestine. Bile acid losses increased with the duration of gastrointestinal symptoms. Significantly lower SeHCAT values were encountered in patients with gastric retention, whereas the occurrence of amyloid deposits in small-intestinal biopsy specimens was without effect on SeHCAT retention. Bile acid malabsorption is frequently encountered in familial amyloidosis with polyneuropathy and seems to be more closely associated with gastrointestinal motility dysfunction than with amyloid deposits in the intestinal mucosa.     

Bacterial Contamination of the Small Bowel Evaluated by Breath Tests, 75Se-Labelled Homocholic-Tauro Acid,and Scanning Electron Microscopy

Eighty-one patients with diarrhoea due to suspected bacterial contamination of the small intestine were investigated with the bile acid breath test (BABT) and ⁷⁵Se-labelled homocholic-tauro acid (SeHCAT), The impact of bile acid malabsorption due to dysfunction of the terminal ileum on BABT was evaluated. The group of patients with abnormal BABT, notably the 6-h accumulated value, showed a high frequency of reduced SeHCAT values (p < 0.01), indicating that a reliable test for bile acid malabsorption is indispensable for interpreting the BABT in the investigation of small-intestinal bacterial overgrowth. The results of the ¹⁴C-D-xylose breath test were compared with the outcome of the combined SeHCAT-BABT in 44 patients. In contrast to previous findings no correlation between the two breath tests was found. On the contrary, a significant negative correlation was encountered (p < 0.01) for patients in whom either breath test was abnormal. Scanning electron microscopy for demonstration of adherent microorganisms was included in the investigations. No correlations were found with the outcomes of the different breath tests. The effect of antibiotic treatment was evaluated with regard to symptoms and breath tests. The results of the investigation indicate that different tests are needed for the diagnosis of bacterial overgrowth of the small intestine, because of the different metabolic-characteristics of the contaminating bacteria.     

Bacterial contamination of the small bowel evaluated by breath tests, 75Se-labelled homocholic-tauro acid, and scanning electron microscopy

Eighty-one patients with diarrhoea due to suspected bacterial contamination of the small intestine were investigated with the bile acid breath test (BABT) and 75Se-labelled homocholic-tauro acid (SeHCAT). The impact of bile acid malabsorption due to dysfunction of the terminal ileum on BABT was evaluated. The group of patients with abnormal BABT, notably the 6-h accumulated value, showed a high frequency of reduced SeHCAT values (p less than 0.01), indicating that a reliable test for bile acid malabsorption is indispensable for interpreting the BABT in the investigation of small-intestinal bacterial overgrowth. The results of the 14C-D-xylose breath test were compared with the outcome of the combined SeHCAT-BABT in 44 patients. In contrast to previous findings no correlation between the two breath tests was found. On the contrary, a significant negative correlation was encountered (p less than 0.01) for patients in whom either breath test was abnormal. Scanning electron microscopy for demonstration of adherent microorganisms was included in the investigations. No correlations were found with the outcomes of the different breath tests. The effect of antibiotic treatment was evaluated with regard to symptoms and breath tests. The results of the investigation indicate that different tests are needed for the diagnosis of bacterial overgrowth of the small intestine, because of the different metabolic characteristics of the contaminating bacteria.     

Role of bile acids and bile acid binding agents in patients with collagenous colitis

BACKGROUND: In a retrospective study bile acid malabsorption was observed in patients with collagenous colitis. AIMS: To study the occurrence of bile acid malabsorption and the effect of bile acid binders prospectively in patients with chronic diarrhoea and collagenous colitis. METHODS: Over 36 months all patients referred because of chronic diarrhoea completed a diagnostic programme, including gastroscopy with duodenal biopsy, colonoscopy with biopsies, and the (75)Se-homocholic acid taurine ((75)SeHCAT) test for bile acid malabsorption. Treatment with a bile acid binder (cholestyramine in 24, colestipol in three) was given, irrespective of the results of the (75)SeHCAT test. RESULTS: Collagenous colitis was found in 28 patients (six men, 22 women), 27 of whom had persistent symptoms and completed the programme. Four patients had had a previous cholecystectomy or a distal gastric resection. The (75)SeHCAT test was abnormal in 12/27 (44%) of the collagenous colitis patients with (75)SeHCAT values 0.5-9.7%, and normal in 15 patients (56%). Bile acid binding treatment was followed by a rapid, marked, or complete improvement in 21/27 (78%) of the collagenous colitis patients. Rapid improvement occurred in 11/12 (92%) of the patients with bile acid malabsorption compared with 10/15 (67%) of the patients with normal (75)SeHCAT tests. CONCLUSION: Bile acid malabsorption is common in patients with collagenous colitis and is probably an important pathophysiological factor. Because of a high response rate without serious side effects, bile acid binding treatment should be considered for collagenous colitis, particularly patients with bile acid malabsorption.     

Bile acid malabsorption in Crohn's disease and indications for its assessment using SeHCAT.

Patients with Crohn's disease who suffer from longstanding diarrhoea that does not respond to conventional treatment pose a common clinical problem. Bile acid malabsorption is a possible cause, although its prevalence and clinical importance is unclear. This paper explores the clinical indications for referring patients with Crohn's disease for bile acid assessment and the extent of bile acid malabsorption in this selected group of patients. The selenium labelled bile acid SeHCAT was used to assess the effect of disease on the integrity of the enterohepatic circulation. Altogether 76% of the patients referred for bile acid assessment had longstanding diarrhoea that had not responded to conventional anti-diarrhoeal treatment or an increase in steroid therapy as their sole or predominant symptom. Ninety per cent of patients with bowel resections, almost exclusively ileocaecal, had abnormal SeHCAT retention (< 5% at seven days). Twenty eight per cent of patients with Crohn's disease who had not undergone resection 28% had a SeHCAT retention < 5%, signifying bile acid malabsorption. Nineteen of 22 patients given cholestyramine treatment subsequent to the SeHCAT test had a good symptomatic response. In conclusion, the prevalence of bile acid malabsorption in this selected group with Crohn's disease is sufficiently high to justify performing the SeHCAT test in order to separate the various differential diagnoses.     

Chronic diarrhoea after radiotherapy for gynaecological cancer: occurrence and aetiology.

The occurrence of chronic diarrhoea was evaluated in 173 consecutive patients previously treated with radiation for gynaecological cancer. A survey of gastrointestinal symptoms showed a high frequency of diarrhoea; 13% of the patients had 21 or more bowel movements a week and 3% had 28 or more. Significantly more patients who had a cholecystectomy were in the group with diarrhoea (chi 2 = 6.26; p less than 0.02). Twenty patients with chronic or intermittent diarrhoea were subject to extended gastrointestinal investigation. Bile acid malabsorption was evaluated by the 75Selenahomocholic acid-taurine test (SeHCAT). Bile acid malabsorption was found in 13 (65%) of the 20 patients further investigated, of whom seven had extremely low whole body retention values, which is consistent with severe malabsorption. The results suggest that bile acid malabsorption is a common cause of diarrhoea after radiation treatment for gynaecological cancer. Bacterial contamination was diagnosed in nine patients (45%) by the [14C]-D-xylose breath test or by the cholyl-[14C]-glycine breath test in combination with a normal test for bile acid malabsorption. All patients with vitamin B-12 deficiency, who were tested for bile acid malabsorption, had low retention times for the SeHCAT (p = 0.05). A significant decline in the frequency of diarrhoea was found after treatment with antibiotics or bile acid sequestrants, or both, in combination with a reduced fat diet.     

Bile Acid Malabsorption in Patients with Chronic Diarrhoea

The presence of bile acid malabsorption was studied in 24 patients with chronic diarrhoea without established cause despite extensive investigations. Bile acid absorption was evaluated with the ⁷⁵Se-homocholic acid taurine (SeHCAT) test. A therapeutic trial of cholestyramine was performed in 11 patients. Fourteen of the patients (58%) showed evidence of bile acid malabsorption. Of the 11 patients who were treated with cholestyramine, 3 had no improvement of their diarrhoea and also had a normal SeHCAT test result. Of the other eight patients, who also had pathologic SeHCAT test result, five improved on treatment, whereas three had no change of their diarrhoea. Seven of the 24 patients had a previous history of cholecystectomy. Four of them showed bile acid malabsorption; three of these were treated with cholestyramine and responded favourably. The results suggest that bile acid malabsorption may be common in chronic diarrhoea patients but may not always be the primary cause of diarrhoea.     

Outcome of Gastrointestinal Complications after Liver Transplantation for Familial Amyloidotic Polyneuropathy

Background: Gastrointestinal disturbances are important prognostic factors for mortality and morbidity after liver transplantation for familial amyloidotic polyneuropathy (FAP). However, the impact of liver transplantation on malabsorption and bacterial small-bowel contamination has not been evaluated. Methods: Twenty-three FAP patients were available for the study. They were examined for gastrointestinal disturbances as a part of the evaluation for liver transplantation for FAP. Bile acid malabsorption was diagnosed with the [75Se]-homocholic acid taurate (SeHCAT) test; fat malabsorption by measuring faecal fat excretion; and bacterial small-bowel contamination with the hydrogen breath test (HBT). Results: No significant improvement of malabsorption test results were noted from the pre-transplant evaluation 8 months (range, 2-20 months) before transplantation to the post-transplant evaluation performed a median of 20 months (range, 9-62 months) after the procedure. The SeHCAT test result became abnormal in two patients and normal in one, and changes in the test correlated with the time the patients were waiting for transplantation. Faecal fat excretion after transplantation correlated with duration of the disease and with fat excretion before transplantation. A significantly increased fat excretion was noted at the post-transplant evaluation. A change in HBT result was noted in only one patient, in whom the test result became normal; pre-transplant values correlated with those obtained after transplantation. Conclusion: For most FAP patients no improvement in gastrointestinal function was found after transplantation. The finding underlines the importance of an early transplantation before the patients have developed gastrointestinal dysfunction.     

Outcome of gastrointestinal complications after liver transplantation for familial amyloidotic polyneuropathy

BACKGROUND: Gastrointestinal disturbances are important prognostic factors for mortality and morbidity after liver transplantation for familial amyloidotic polyneuropathy (FAP). However, the impact of liver transplantation on malabsorption and bacterial small-bowel contamination has not been evaluated. METHODS: Twenty-three FAP patients were available for the study. They were examined for gastrointestinal disturbances as a part of the evaluation for liver transplantation for FAP. Bile acid malabsorption was diagnosed with the [75Se]-homocholic acid taurate (SeHCAT) test; fat malabsorption by measuring faecal fat excretion; and bacterial small-bowel contamination with the hydrogen breath test (HBT). RESULTS: No significant improvement of malabsorption test results were noted from the pre-transplant evaluation 8 months (range, 2-20 months) before transplantation to the post-transplant evaluation performed a median of 20 months (range, 9-62 months) after the procedure. The SeHCAT test result became abnormal in two patients and normal in one, and changes in the test correlated with the time the patients were waiting for transplantation. Faecal fat excretion after transplantation correlated with duration of the disease and with fat excretion before transplantation. A significantly increased fat excretion was noted at the post-transplant evaluation. A change in HBT result was noted in only one patient, in whom the test result became normal; pre-transplant values correlated with those obtained after transplantation. CONCLUSION: For most FAP patients no improvement in gastrointestinal function was found after transplantation. The finding underlines the importance of an early transplantation before the patients have developed gastrointestinal dysfunction.     

Relationship between morphological findings and function of the small intestine in familial amyloidosis with polyneuropathy

Twenty-seven patients with familial amyloidosis with polyneuropathy were studied with regard to the morphology of the small intestine, and this was correlated to symptoms and malabsorption features. The mucosa was normal in all cases investigated by the dissecting microscope, the light microscope, and the scanning electron microscope. Amyloid was demonstrated in 83% of the cases by the presence of green birefringent material in the biopsy specimens stained with alkaline Congo red and examined in polarized light. Nineteen patients had steatorrhea, and 12 had pathological D-xylose test results. The degree of amyloid infiltration did not correlate with these data, nor did the symptomatic state correlate with the amount of amyloid in the biopsy specimens. The surface ultrastructure was normal when investigated by means of the scanning electron microscope in all patients except five in whom the glycocalyx was altered. As a group, however, those five did not differ in any respect from the rest of the patients. Rod-shaped microorganisms were shown to adhere to the surface in one patient. The results suggest that mechanisms other than bowel-wall deposition of amyloid cause the dysfunction of the gastrointestinal tract in familial amyloid polyneuropathy.     

Bile acid malabsorption investigated by selenium-75-homocholic acid taurine (SeHCAT) scans: Causes and treatment responses to cholestyramine in 298 patients with chronic watery diarrhoea

Background

The liver produces and secretes bile acids into the small intestine. In the small intestine, most of the bile acids are absorbed in the distal ileum with portal vein transportation back to the liver and resecretion (enterohepatic recycling). Increased spillover of bile acids from the small intestine into the colon (bile acid malabsorption) may affect the secretion of colonic water and electrolytes and result in watery diarrhoea.The aim of this study was to investigate the frequency of bile acid malabsorption and treatment responses to cholestyramine with ⁷⁵SeHCAT scanning among patients suffering from chronic watery diarrhoea.

Methods

This was a retrospective study that included all patients who received a ⁷⁵SeHCAT scan over a five-year period (2004-2009).

Results

In total, 298 patients (198 females, 100 men) with a median age of 42 years (range 16-82 years) were investigated.Bile acid malabsorption (⁷⁵SeHCAT retention < 15% after seven days) was identified in 201 patients (68%, 95% confidence interval (CI): 62%-73%). Bile acid malabsorption due to ileal dysfunction (Type I) was found in 77 patients, idiopathic bile acid malabsorption (Type II) was found in 68 patients and 56 patients with other conditions had bile acid malabsorption (Type III).Of the 150 patients who were able to take cholestyramine continuously, 108 patients (71%, CI: 63%-78%) reported a positive effect on their bowel habits.

Conclusions

Bile acid malabsorption is a frequent problem in patients with chronic watery diarrhoea. Treatment with bile acid binders was effective regardless of type and severity.     

Impact of bile acid malabsorption on steatorrhoea and symptoms in patients with chronic diarrhoea

OBJECTIVE: Bile acids are important for fat absorption. The relationship between bile acid malabsorption and steatorrhoea and gastrointestinal symptoms in patients with chronic diarrhoea has only been studied on a limited scale. DESIGN: Ninety-four patients referred for chronic diarrhoea were prospectively investigated with the 75SeHCAT test, a faecal fat excretion test and registration of symptoms in addition to the standard clinical work-up. METHODS: The correlation between the 75SeHCAT value and the faecal fat excretion was calculated for different groups of patients. Symptoms were registered in a questionnaire over a period of seven consecutive days. RESULTS: Forty-two patients had a 75SeHCAT value < 10%. Mild steatorrhoea was common in patients with non-organic bile acid malabsorption (50%) and in patients with functional diarrhoea (38%). There was no correlation between low 75SeHCAT values and steatorrhoea, although some patients with severe organic disease had a concomitant malabsorption of fat and of bile acids. In coeliac disease, severe steatorrhoea was common even in patients with high 75SeHCAT values. Patients with bile acid malabsorption had more frequent (P < 0.008) and looser (P= 0.0021) stools compared with patients with functional diarrhoea. There was no difference in abdominal pain, distension or flatulence. CONCLUSION: Mild steatorrhoea is common in both non-organic bile acid malabsorption and functional diarrhoea. The 75SeHCAT value cannot predict the risk of steatorrhoea. The high prevalence of bile acid malabsorption in patients with chronic diarrhoea and the absence of specific symptoms, except frequent and more liquid stools, indicates that the 75SeHCAT test should be performed early in the investigation of these patients.     

Relationship between Morphological Findings and Function of the Small Intestine in Familial Amyloidosis with Polyneuropathy

Twenty-seven patients with familial amyloidosis with polyneuropathy were studied with regard to the morphology of the small intestine, and this was correlated to symptoms and malabsorption features. The mucosa was normal in all cases investigated by the dissecting microscope, the light microscope, and the scanning electron microscope. Amyloid was demonstrated in 83% of the cases by the presence of green birefringent material in the biopsy specimens stained with alkaline Congo red and examined in polarized light. Nineteen patients had steatorrhea, and 12 had pathological D-xylose test results. The degree of amyloid infiltration did not correlate with these data, nor did the symptomatic state correlate with the amount of amyloid in the biopsy specimens. The surface ultrastructure was normal when investigated by means of the scanning electron microscope in all patients except five in whom the glycocalyx was altered. As a group, however, those five did not differ in any respect from the rest of the patients. Rod-shaped microorganisms were shown to adhere to the surface in one patient. The results suggest that mechanisms other than bowel-wall deposition of amyloid cause the dysfunction of the gastrointestinal tract in familial amyloid polyneuropathy.     

Normal or increased bile acid uptake in isolated mucosa from patients with bile acid malabsorption

INTRODUCTION: Bile acid malabsorption as reflected by an abnormal Se-labelled homocholic acid-taurine (SeHCAT) test is associated with diarrhoea, but the mechanisms and cause-and-effect relations are unclear. OBJECTIVES: Primarily, to determine whether there is a reduced active bile acid uptake in the terminal ileum in patients with bile acid malabsorption. Secondarily, to study the linkage between bile acid malabsorption and hepatic bile acid synthesis. METHODS: Ileal biopsies were taken from patients with diarrhoea and from controls with normal bowel habits. Maximal active bile acid uptake was assessed in ileal biopsies using a previously validated technique based on uptake of C-labelled taurocholate. To monitor the hepatic synthesis, 7alpha-hydroxy-4-cholesten-3-one, a bile acid precursor, was assayed in blood. The SeHCAT-retention test was used to diagnose bile acid malabsorption. RESULTS: The taurocholate uptake in specimens from diarrhoea patients was higher compared with the controls [median, 7.7 (n=53) vs 6.1 micromol/g per min (n=17)] (P<0.01) but no difference was seen between those with bile acid malabsorption (n=18) versus diarrhoea with a normal SeHCAT test (n=23). The SeHCAT values and 7alpha-hydroxy-4-cholesten-3-one were inversely correlated. CONCLUSIONS: The data do not support bile acid malabsorption being due to a reduced active bile acid uptake capacity in the terminal ileum.     

Role of bile acids in lymphocytic colitis

BACKGROUND/AIMS: A high prevalence of bile acid malabsorption and a high response rate to bile acid binders are seen in collagenous colitis. Our aim was to explore if bile acids play a role in lymphocytic colitis, which is unknown. METHODOLOGY: Patients with lymphocytic colitis completed a diagnostic program, including the 75SeHCAT (75Se-labelled homocholic acid-taurine) test and registration of symptoms. Prevalence of bile acid malabsorption, response to bile acid binders, correlation between 75SeHCAT and histopathology were determined. The 75SeHCAT values were compared with 29 controls. RESULTS: Two out of 23 with lymphocytic colitis had a 75SeHCAT retention < or = 10%. The median 75SeHCAT value in lymphocytic colitis, 24% (range: 1.7-53), was lower than in the control group, 38% (range: 8-91) (P < 0.02). Forty-six per cent (6/13) responded to bile acid binders. No correlation was found between the 75SeHCAT values and degree of colonic inflammation. Two patients developed collagenous colitis. CONCLUSIONS: Bile acid malabsorption is more uncommon in lymphocytic colitis than in collagenous colitis. The 75SeHCAT values, however, suggest a role of bile acids in lymphocytic colitis. The conversion of 2 patients to collagenous colitis and disturbed absorption of bile acids also in lymphocytic colitis is consistent with the idea that the two forms represent variants of the same disease.     

Impact of gastrointestinal dysfunction on survival after liver transplantation for familial amyloidotic polyneuropathy

Liver transplantation is the only effective treatment of familial amyloidotic polyneuropathy type I (FAP). The aim of the present investigation was to identify factors at the time of submission for transplantation that had impact on survival, with special reference to gastrointestinal disturbances. All 28 liver-transplanted FAP patients evaluated at Umeå University Hospital were included in the study. A modified body mass index was used to assess nutritional status. Intestinal examinations were performed to diagnose bile acid malabsorption, gastric retention, and bacterial contamination of the small bowel. A significantly improved survival rate was found for patients in a good nutritional state (P=0.002). Peripheral neurological symptoms were unrelated to survival, whereas increased mortality was found for patients with bile acid malabsorption (P<0.05). Bacterial contamination and gastric retention were common complications of the disease. In conclusion, malabsorption and malnutrition have a profound impact on the outcome of liver transplantation for familial amyloidotic polyneuropathy.The study was supported by grants from the patients association FAMY, Umeå Health District, the Swedish Medical Research Council, grant 19X-11240, Umeå University and the Joint Committee of the Northern Health Districts.     

Bile Acid Malabsorption in AIDS-Associated Chronic Diarrhea: A Prospective 1-Year Study

Objectives: In patients with chronic diarrhea associated with acquired immunodeficiency syndrome, bile acid malabsorption, very rarely investigated, may have an important pathogenetic role. Methods: In this 1-yr prospective study, 15 patients with AlDS-associated chronic diarrhea and 10 AIDS-controls were studied for bile acid malabsorption by means of the SeHCAT abdominal retention test. The patients with diarrhea underwent the glucose hydrogen breath test to identify any bacterial proliferation in the small bowel. Results: the chronic diarrhea group, only one case of small bowel bacterial overgrowth, and seven cases (47%) with generally severe bile acid malabsorption, were observed. Among the controls, only one had an abnormal low SeHCAT retention. In hoth cases with Cryptosporidium infection, the SeHCAT test was pathological. Conclusions: These data are of clinical importance for the pathogenetic study of AIDS-associated chronic diarrhea and for specific treatment with cholestyramine.     

Bile acid malabsorption after intestinal bypass surgery for obesity. A comparison between jejunoileal shunt and biliointestinal bypass

Seventeen patients were operated on with intestinal shunts for morbid obesity, in eight a biliointestinal bypass (BI) was constructed and in the rest a conventional jejunoileal (JI)-shunt. The reduction in weight was similar in both groups, and so was malabsorption of fat, but the BI-group had significantly less bowel motions with less watery diarrhoea. Bile acid malabsorption was measured both chemically by estimating the total amount of faecal bile acids excreted, as well as indirectly by using a 75Se-labelled synthetic bile acid (SeHCAT). Both techniques revealed a substantial loss of bile acid after both types of operation, but patients with BI bypass surgery had significantly lower elimination time of the bile acid than those with JI-shunts. There was a significant negative correlation between SeHCAT retention and total faecal bile acids. However, some patients with low SeHCAT retention had normal or even reduced output of faecal bile acids. Estimation of faecal bile acids may display false negative results when the bile acid pool is decreased. The SeHCAT-test seems to be a better technique for measuring bile acid losses. The study suggests that BI bypass surgery for obesity seems to be advantageous over the JI shunt in reducing the postoperative loss of bile acids and choleretic diarrhoea, without influencing the weight loss.     

Long-term course in collagenous colitis and the impact of bile acid malabsorption and bile acid sequestrants on histopathology and clinical features.

BACKGROUND: Bile acid malabsorption is common in collagenous colitis, although long-term follow-up data on the impact of bile acids are limited. The aim was to study whether bile acid malabsorption is a permanent finding, with an impact on histopathology and clinical features in collagenous colitis. METHODS: The objective was to reinvestigate 27 patients with collagenous colitis > or = 3 years after index investigation. The clinical course was evaluated by means of an interview, a review of the hospital records and registration of symptoms over a period of 7 days. The patients were invited to undergo a repeat colonoscopy and 75SeHCAT measurement. Initial and follow-up data and 75SeHCAT values from 29 controls were compared. RESULTS: The median follow-up time was 4.2 (range 3-5.3) years. Twenty-two patients underwent a repeat 75SeHCAT test, 23 patients a colonoscopy and in 25 patients the clinical course could be evaluated. The 75SeHCAT values were abnormal in 32% at follow-up versus 44% at index, and the median retention value was 19% (range 2-69) versus 12% (range 0.5-41) (P = 0.024) although lower than in the control groups figure of 38% (range 8-91) (P < 0.005). Histopathology had improved independently of bile acid malabsorption, gender, smoking and autoimmune disease at follow-up. Four were normalized. Patients on bile acid binders had no significant change of histopathology. Four patients had recovered, seven displayed an intermittent course and 14 had continuous diarrhoea. CONCLUSIONS: Collagenous colitis and bile acid malabsorption seem to be associated yet independent disorders. The histopathology improves during the long-term course although only a few patients resolve.     

Comparison of maximal postprandial serum cholylglycine concentration with the retention of 75Se-homotaurocholic acid in ileal dysfunction

The retention of 75Se-homotaurocholic acid (75SeHCAT) was measured in 12 healthy controls and in 21 patients with Crohn's disease and compared with the maximum postprandial rise in the serum concentration of cholylglycine (CG) in order to detect bile acid malabsorption. The retention of 75SeHCAT was lowered in all patients with inflammation or resection of the terminal ileum over a length more than 20 cm. In 64% of these patients bile acid malabsorption could also be detected by the absence of a significant rise of the postprandial CG serum level but only if the loss of the ileal function exceeded 30 cm. Although less sensitive than the 75SeHCAT retention, the CG method is simpler to apply in terms of laboratory technology and does not involve exposure to radioactivity. The CG method appears to be of use to detect bile acid malabsorption in certain cases. In the case of negatively if still bile acid malabsorption is suspected more sensitive tests such as 75SeHCAT retention should be carried out to further evaluate bile acid malabsorption.