Effect of cholecystectomy on mouth-to-cecum transit of a liquid meal

Postcholecystectomy diarrhoea rate and predictive factors: a systematic review of the literature

OBJECTIVES

Cholecystectomy is one of the most common surgical procedures performed worldwide to treat gallstone-related disease. Postcholecystectomy diarrhoea (PCD) is a well-reported phenomenon, however, the actual rate, predictive factors and mechanism of action have not been well determined. A systematic review was undertaken to determine the rate and predictive factors associated with diarrhoea in the postcholecystectomy setting.

METHODS

The review was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocol. Databases searched included Medline, Embase, Pubmed, Cochrane and Google Scholar up to 29 September 2020. The inclusion criteria consisted of cohort studies or randomised trials which investigated the rate of PCD and predictive factors. Case reports, case series, conference abstracts and expert opinion pieces were excluded as were other systematic reviews as all the original articles from those reviews were included in this review. Papers that did not include PCD as a separate entity were excluded. Bias assessment was performed using the Newcastle-Ottawa Scale for cohort studies and the Cochrane risk of bias tool for randomised controlled trials as appropriate. Data were extracted by two authors (AF and JAA) and an overall rate of PCD was calculated. Predictive factors were also extracted and compared between studies.

RESULTS

1204 papers were obtained and 21 were found to contain relevant information about PCD, including the number of patients developing diarrhoea, method of symptom assessment and time of onset postcholecystectomy. A pooled total of 3476 patients were included across the identified studies with 462 (13.3%) patients developing PCD. Possible predictive factors varied across all studies, with characteristics such as gender, age and weight of patients postulated as being predictive of PCD, with no agreement across studies.

DISCUSSION

PCD is therefore relatively common (13.3%). This has important implications for patient consent. Patients ought to be investigated early for bile acid diarrhoea in suspected PCD. More studies are required to determine the possible predictive factors for PCD. Limitations of the study included that most studies were not powered for calculation of PCD, and assessment methods between studies varied.

PROSPERO REGISTRATION NUMBER

CRD42019140444.

LC-MS-based plasma metabolomics study of the intervention effect of different polar parts of hawthorn on gastrointestinal motility disorder rats

Dyspepsia, one of the most prevalent diseases of the digestive tract that impacts the quality of patient life, is mainly caused by gastrointestinal motility disorder. Hawthorn is a commonly used traditional Chinese medicine for treating dyspepsia, and has been proven to improve gastrointestinal motility. Herein, a rat model of gastrointestinal motility disorder was established by subcutaneous injection with atropine. The modeled rats were treated with four polar parts (T1-4 in descending polarity, corresponding to water, n-butanol, ethyl acetate and petroleum ether extracts, respectively) of hawthorn. Through metabolomics analysis, a total of 20 significantly metabolites were identified with significant changes in their abundance levels and these metabolites were related to many metabolic pathways such as amino acid metabolism and primary bile acid biosynthesis. The results showed that T3 had the best therapeutic effect of promoting gastrointestinal motility. Other parts showed no obvious therapeutic effect, demonstrating that the effective components of hawthorn may be compounds of medium polarity. T3 might achieve good therapeutic effects owing to the gastrointestinal motility promotion activity, and by rectifying the disturbed metabolic pathways in the gastrointestinal motility disorder model.

Bowel habits and bile acid malabsorption in the months after cholecystectomy

OBJECTIVE

Bile acid malabsorption has been supposed to play a major pathogenetic role in postcholecystectomy diarrhea. Therefore, the aim of this study was to define the effect of cholecystectomy (CHE) on bowel habits and bile acid absorption.

METHODS

Fifty-one patients were prospectively studied before, at 4 wk, and 12 wk after elective CHE for changes of bowel habits, occurrence of diarrhea, and signs of bile acid malabsorption. Bowel habits were assessed by interview. Serum concentrations of 7alpha-hydroxy-4-cholesten-3-one were used as a marker of bile acid malabsorption. Statistics were performed with the McNemar chi2 test for discrete values and Student's paired t test for continuous values.

RESULTS

After CHE, there was an increase of patients reporting more than one bowel movement per day (from 22% before CHE to 51% [p < 0.001] and 45% [p < 0.005] at 1 month and 3 months after CHE, respectively) and of patients reporting loose stools (from 2% to 47% [p < 0.001] and 33% [p < 0.001], respectively). Three months after CHE, three patients (6%) reported intermittent diarrhea. Serum levels of 7alpha-hydroxy-4-cholesten-3-one increased from 25.4+/-14.5 ng/ml to 46.5+/-29.5 ng/ml (p < 0.001) and 52.5+/-33.0 ng/ml (p < 0.001), respectively. Unexpectedly, changes of 7alpha-hydroxy-4-cholesten-3-one in serum were unrelated to changes of bowel habits.

CONCLUSIONS

CHE results in considerable changes of bowel habits and an increased loss of bile acids from the intestine in some patients. Bile acid malabsorption, however, may not explain changes of bowel habits after CHE.

The effect of aging on oro-cecal transit time in normal subjects and patients with gallstone disease

To ascertain whether aging and/or cholelithiasis can influence oro-cecal transit time (OCTT), we studied a total of 70 subjects, i.e., 10 healthy young adult controls, 22 healthy elderly controls, 18 elderly cholelithiasis patients and 20 elderly subjects with a history of cholecystectomy for gallstones. OCTT was measured by means of the hydrogen breath test after administering a liquid meal of 10 g of lactulose in 200 mL of water, and collecting exhaled breath samples every 10 minutes for 200 minutes. Of all subjects in the group of patients with a history of cholecystectomy, 6/20 were non-hydrogen producers, and therefore were not included in the study. The OCTT was found to be significantly longer in healthy elderly controls, than in healthy young adult controls; the elderly subjects who had undergone cholecystectomy had a longer OCTT than the healthy elderly controls, while no difference was detected when compared to elderly patients with gallstones. In conclusion, OCTT seems to increase in healthy aging. Cholecystectomy also increases OCTT in the elderly, suggesting a link between intestinal motility and the biliary tract which may be of pathophysiological significance.

Lactulose hydrogen breath test in orocecal transit assessment. Critical evaluation by means of scintigraphic method

Orocecal transit time can be studied easily using the hydrogen breath test with lactulose, but the method has some important limitations. The orocecal transit time of 10 patients suffering from irritable bowel syndrome was measured twice, at a one-week interval, by breath test and scintigraphy simultaneously using an aqueous solution of 20 g lactulose containing 74 MBq of [99mTc]DTPA. Abdominal radioactivity and alveolar hydrogen values obtained every 5 min were noted and used to obtain the following: orocecal transit time by the two methods; ileocecal lactulose flow; total and per gram of lactulose hydrogen production; mean hydrogen concentration during the right colon filling; and measurement error of the breath test with respect to the scintigraphy. In the case of the breath test, the orocecal transit time intrapatient reproducibility was better (coefficient of variation = 13.5%) when a hydrogen threshold increment of 5 ppm was used; the best correlation with the scintigraphic measurement was observed at this threshold (r = 0.90, P < 0.001). The breath test overestimated orocecal transit time with the error correlating negatively and significantly with the total hydrogen production and, particularly, the mean hydrogen concentration (r = 0.79, P < 0.01): for a mean hydrogen concentration of more than 15 ppm, the error was negligible, while within this value there was a noticeable overestimation. To conclude, the lactulose hydrogen breath test is capable of giving an accurate measurement of orocecal transit time if a hydrogen threshold increment of 5 ppm is chosen and if the mean hydrogen concentration in the first 30 min of the right colon filling is taken into account.

The effect of gastric pH on the absorption of controlled-release theophylline dosage forms in humans

The bioavailability of three marketed controlled-release dosage forms and a reference solution of theophylline was studied in eight subjects with normal gastric fluid acidity and seven subjects who were achlorhydric. Gastric pH was monitored with a Heidelberg capsule. One of the controlled-release dosage forms dissolved more rapidly in vitro when exposed to acid conditions, one dissolved more rapidly in pH 7.5 media, and the third dissolved at a rate independent of pH. Using a crossover design, each subject received each dosage form twice. Blood was sampled for up to 47 hr after each dose, and serum was assayed for theophylline by HPLC. The product which dissolved more rapidly under acid conditions in vitro exhibited a 3 hr longer Tmax in the achlorhydrics compared to the normal subjects. The product which dissolved more rapidly in the pH 7.5 media exhibited a relatively higher AUC(0-infinity) in the achlorhydric subjects than in normal subjects after the AUC data were normalized for clearance differences between the two subject groups. The in vivo bioavailability of these dosage forms could be related to the in vitro dissolution characteristics for some parameters. However, with the exception of the mean Tmax values, the mean bioavailability parameters differed by less than 20% between the two subjects groups.

Effects of cholecystectomy on the kinetics of primary and secondary bile acids

Removal of the gallbladder is thought to increase formation and pool size of secondary bile acids, mainly deoxycholic acid (DCA), by increased exposure of primary bile acids (cholic acid [CA], chenodeoxycholic acid [CDCA]) to bacterial dehydroxylation in the intestine. We have tested this hypothesis by simultaneous determination of pool size and turnover of DCA, CA, and CDCA in nine women before and at various intervals after removal of a functioning gallbladder. An isotope dilution technique using marker bile acids labeled with stable isotopes (2H4-DCA, 13C-CA, 13C-CDCA) was used. After cholecystectomy, concentration and output of bile acids relative to bilirubin increased (P less than 0.02) in fasting duodenal bile and cholesterol saturation decreased by 27% (P less than 0.05) consistent with enhanced enterohepatic cycling of bile acids. Three months after removal of the gallbladder bile acid kinetics were in a new steady state: pool size and turnover of CDCA were unchanged. Synthesis of CA, the precursor of DCA, was diminished by 37% (P = 0.05), probably resulting from feedback inhibition by continuous transhepatic flux of bile acids. The fraction of CA transferred after 7 alpha-dehydroxylation to the DCA pool increased from 46 +/- 16 to 66 +/- 32% (P less than 0.05). However, this enhanced transfer did not lead to increased input or size of the DCA pool, because synthesis of the precursor CA had decreased.

Effect of jejunal infusion of bile acids on small bowel transit and fasting jejunal motility in man

The effect of jejunal infusion of glycochenodeoxycholic acid and glycocholic acid on small bowel transit time, fasting jejunal motility and serum bile acid concentrations was investigated in groups of five to six healthy subjects. Glycochenodeoxycholic acid at a concentration of 15 mmol/l (total amount: 5 mmol) and glycocholic acid 15 mmol/l (total amount: 5 mmol), both with lecithin 2.5 mmol/l, delayed (p less than 0.02) small bowel transit when compared with a bile acid free infusion [158.3 (12.5) min v 111.7 (17.6) min and 103.3 (21.8) min v 70.0 (14.9) min], inhibited (p less than 0.01 and p less than 0.05 respectively) the percentage duration of pressure activity of phase 2 [13.1 (1.8)% v 28.1 (3.4)% and 29.2 (5.5)% v 34.9 (3.9)%], but did not change duration of migrating motor complex, or of its phases. Glycochenodeoxycholic acid 10 mmol/l (total amount: 3.3 mmol), either with or without lecithin, did not delay small bowel transit significantly [145.0 (13.2) min v 115.0 (19.5) and 90.0 (11.7) min v 84.0 (8.3)]. When bile acids were infused, serum bile acid curves were similar to those obtained after a liquid meal and the peak serum bile acid concentration occurred 33.7 (6.6) min before (p less than 0.001) completion of small bowel transit. These observations suggest a role for endogenous bile acids in the regulation of small gut motility.