Altered bile acid metabolism in patients with constipation-predominant irritable bowel syndrome and functional constipation

Objective. Bile acids are derived from cholesterol and are potent physiological laxatives. The aim of this study was to investigate whether bile acid synthesis is altered in constipation. Material and methods. Female patients with constipation (23 IBS-C, 4 functional constipation (FC)) were studied and compared with non-constipated subjects (16 IBS-D, 20 healthy women). Body mass index (BMI), blood lipids, lanosterol, sitosterol, colonic transit (oro-anal transit time (OATT), reference=4.3 days) and stool frequency were measured. C4 (7-α-hydroxy-4-cholesten-3-one) levels reflecting bile acid synthesis were measured at 0800 h and 1300 h. Results. When all the groups of constipated and non-constipated subjects were compared, it was found that only stool frequency and OATT differed between groups (p <0.001). When constipated patients were categorized according to OATT, absence of the usual C4 increase at lunchtime was noted in 82% of patients with delayed OATT compared with 17% in subjects with normal OATT (p <0.001). Symptom severity did not differ between groups. A subset of the patients with severely delayed OATT had markedly elevated C4 levels. Conclusions. Patients with IBS-C and FC have marked changes in bile acid synthesis in relation to colonic transit. The diurnal rhythm is altered in the slow transit colon when there is no C4 peak at lunchtime. Alterations in bile acid metabolism may be implicated in the pathophysiology of constipation.     

Inhibition of ileal bile acid transporter: An emerging therapeutic strategy for chronic idiopathic constipation

Chronic idiopathic constipation is a common disorder of the gastrointestinal tract that encompasses a wide profile of symptoms. Current treatment options for chronic idiopathic constipation are of limited value; therefore, a novel strategy is necessary with an increased effectiveness and safety. Recently, the inhibition of the ileal bile acid transporter has become a promising target for constipation-associated diseases. Enhanced delivery of bile acids into the colon achieves an accelerated colonic transit, increased stool frequency, and relief of constipation-related symptoms. This article provides insight into the mechanism of action of ileal bile acid transporter inhibitors and discusses their potential clinical use for pharmacotherapy of constipation in chronic idiopathic constipation.     

Study on the characteristics of intestinal motility of constipation in patients with Parkinson's disease

BACKGROUNDConstipation is one of the most important nonmotor symptoms in Parkinson''s disease (PD) patients, and constipation of different severities is closely related to the pathogenesis of PD. PD with constipation (PDC) is considered a unique type of constipation, but its mechanism of formation and factors affecting its severity have been less reported. Understanding the gastrointestinal motility characteristics and constipation classification of PDC patients is essential to guide the treatment of PDC. In this study, the colonic transit test and high-resolution anorectal manometry were used to identify the intestinal motility of PDC to provide a basis for the treatment of PDC.AIMTo investigate the clinical classification of PDC, to clarify its characteristics of colonic motility and rectal anal canal pressure, and to provide a basis for further research on the pathogenesis of PDC.METHODSTwenty PDC patients and 20 patients with functional constipation (FC) who were treated at Xuanwu Hospital of Capital Medical University from August 6, 2018 to December 2, 2019 were included. A colonic transit test and high-resolution anorectal manometry were performed to compare the differences in colonic transit time, rectal anal canal pressure, and constipation classification between the two groups. RESULTSThere were no statistically significant differences in sex, age, body mass index, or duration of constipation between the two groups. It was found that more patients in the PDC group exhibited difficulty in defecating than in the FC group, and the difference was statistically significant. The rectal resting pressure, anal sphincter resting pressure, intrarectal pressure, and anal relaxation rate in the PDC group were significantly lower than those in the FC group. The proportion of paradoxical contractions in the PDC group was significantly higher than that in the FC group. There was a statistically significant difference in the type composition ratio of defecatory disorders between the two groups (P < 0.05). The left colonic transit time, rectosigmoid colonic transit time (RSCTT), and total colonic transit time were prolonged in PDC and FC patients compared to normal values. The patients with FC had a significantly longer right colonic transit time and a significantly shorter RSCTT than patients with PDC (P < 0.05). Mixed constipation predominated in PDC patients and FC patients, and no significant difference was observed. CONCLUSIONPatients with PDC and FC have severe functional dysmotility of the colon and rectum, but there are certain differences in segmental colonic transit time and rectal anal canal pressure between the two groups.     

Fiber intake and colonic transit time in functional constipated patients

BACKGROUND: Patients with functional constipation presenting no response to treatment using fibers supplement represents important clinical issue. AIMS: To evaluate the relations among the amount of ingested fiber, the constipation intensity and the colonic transit time in patients with functional constipation. METHODS: We evaluated 30 patients, presenting no response to treatment using fibers supplement, and 18 healthy volunteers conducting individual inquiry into fibers intake, constipation intensity and the total and segmental colonic transit evaluation using radiopaque markers. RESULTS: In the constipated, despite the good level of fiber intake (26.3 +/- 12.9 g, constipated x 9.3 +/- 5,2 g, control), the symptoms of constipation was serious (score = 21.3 +/- 4.07). Mean total colonic transit was 58.8h. The colonic transit was slower in the constipated group (41.0 +/- 22.8 hours, constipated x 21.8 +/- 18.5h, control). In constipated patients with slow colonic transit (>58.8h) there were colonic inertia (eight), outlet constipation (one) and slow transit in left colon (one), and among constipated patients with normal colonic transit (<58.8h), there were isolated slow transit, in the right colon (nine), left colon (three) and in the rectosigmoid segment (eight). There were no relation among the amount of ingested fiber, constipation intensity and the colon transit. CONCLUSIONS: In the functional constipation the gravity of symptoms does not depend only on the dietary fibers intake, which is not the only responsible for the differences in the colonic transit. The colonic transit can differentiate normal from constipated patients and, among them, those with altered transit that demand approaches distinct of fiber supplementation.     

Regulation of the enteric nervous system in the colon of patients with slow transit constipation

BACKGROUND/AIMS: The cause of impaired motility in patients with slow transit constipation is unknown. To clarify the physiological significance of cholinergic, adrenergic, non-adrenergic non-cholinergic inhibitory nerves in the colon of patients with slow transit constipation, we investigated the enteric nerve responses on lesional and normal bowel segments derived from patients with slow transit constipation and patients who underwent colon resection for colonic cancers. METHODOLOGY: Twenty preparations were taken from the lesional colon of 6 patients with slow transit constipation (2 men and 4 women, aged 23 to 68 years, with a mean age of 44.0 years). Thirty-six preparations were taken from the normal colon of 12 patients with colonic cancer (6 men and 6 women, aged 40 to 60 years, with a mean age of 52.2 years). A mechanographic technique was used to evaluate in vitro muscle responses to acetylcholine, adrenalin, electrical field stimulation of adrenergic and cholinergic nerves before and after treatment with various autonomic nerve blockers. RESULTS: The contraction reaction to acetylcholine in the colon with slow transit constipation was significantly weaker than in the normal colon (P < 0.01). The relaxation reaction to adrenalin in the colon with slow transit constipation was stronger than in the normal colon. The colon with slow transit constipation was more strongly innervated by non-adrenergic non-cholinergic inhibitory nerves than the normal colon, significantly (P < 0.05). CONCLUSIONS: These findings suggest that a decrease of cholinergic nerve and an increase of non-adrenergic non-cholinergic inhibitory nerve play an important role in the impaired motility observed in the colon of patients with slow transit constipation.     

Three variants of pathogenesis and therapy of chronic constipation

Constipation--is a frequent clinical syndrome, which occurs in approximately 15-25% of population. Investigations carried out during the last decade have contributed to a better understanding of the basic mechanisms of chronic constipation (CC), in particular its relationship to colonic transit and anorectal function. All possible causes affecting the occurance of constipation (methabolic, deficiency of fiber, medicines) should be taken into consideration at the patient's examination and anorectal pathology should be excluded. Functional chronic constipation consists of three subtypes: slow transit constipation, dyssynergetic defecation and IBS with predominance of constipation. Rome criteria are useful guidelines for diagnosis of functional constipation. Treatment should be based on evidence-based diagnosis of CC variants. Treatment of an inert colon should be based on enterokinetic type prucalopride and lubiprostone. The possibilities of biophydbectherapy should obligatory be used in dyssynergetic defecation treatment.     

Anorectal dysfunction and delayed colonic transit in patients with progressive systemic sclerosis

We studied 14 unselected patients with progressive systemic sclerosis (PSS), six with constipation, and eight with normal bowel habits. A control group, matched for age and sex, comprised six patients with idiopathic constipation and seven healthy subjects. Anorectal manometry was performed with perfused catheters and segmental colonic transit was measured by a radiopaque marker technique. The resting pressure of the anal canal was significantly reduced in PSS with constipation (P<0.05). The rectoanal inhibitory reflex was detected in only one PSS patient with constipation, but was present in seven of eight PSS patients with normal bowel habits and in all controls (P<0.01). Total and right colonic transit times were significantly delayed in PSS with constipation and in patients with idiopathic constipation (P<0.05). In patients with PSS, colonic transit was delayed and anal sphincter function was impaired in constipated patients, suggesting involvement of both the colon and the anorectum by the disease.     

Relevance of Abdominal Gas Analysis and Transit Study after Colorectal Cancer Surgery

Background: Colon gas volume analysis using abdominal radiographs is an objective and reproducible method for evaluating functional bowel disorders. The aim of this study was to clarify the relevance of colon gas distribution and transit time in rectosigmoid cancer patients after surgery. Methods: Segmental colon gas volume score was calculated using plain abdominal radiography and evaluated in 40 patients who had undergone sphincter-saving resection. Segmental colonic transit time was analysed using radiopaque markers in the same patients. Results: Transit times in the right colon (RCT) were 15.3 ± 1.1 h and in the left colon (LCT) 11.2 ± 1.1 h. Gas volume scores in the RCS and LCS were 1.10 ± 0.13% and 1.06 ± 0.14%, respectively. Neither colonic transit time nor colon gas volume score correlated with the operation methods for rectosigmoid colon cancer. A positive correlation of RCS and a negative correlation of LCS/RCS with ageing were noted in male patients but not in female patients. There was no correlation between RCT and RCS (r = 0.028); however, LCT correlated with LCS (r = 0.318, P < 0.05). The ratio of colonic transit time (LCT/RCT) was 0.84 ± 0.10, while that of colon gas volume score (LCS/RCS) was 1.29 ± 0.21. There was a significant correlation between LCT/RCT and LCS/RCS (r = 0.541, P < 0.001). Conclusions: Analysis of colon gas volume is useful for evaluating colonic transit time in rectosigmoid cancer patients after sphincter-saving surgery.     

Prucalopride accelerates gastrointestinal and colonic transit in patients with constipation without a rectal evacuation disorder

BACKGROUND & AIMS: Prucalopride (PRU) is a selective benzofuran 5-hydroxytryptamine(4)-receptor agonist with gastrointestinal and colonic prokinetic activities. We evaluated the effects of PRU on gastrointestinal and colonic transit in patients with constipation. METHODS: Gastrointestinal and colonic transit were measured over 48 hours in 40 patients who fulfilled modified Rome I criteria for functional constipation. Patients had no evidence of a rectal evacuation disorder. Subjects were randomized to receive a daily dose of 2 or 4 mg PRU or placebo in a double-blind, parallel-group design. Each treatment lasted 7 days. The transit test was performed over the last 48 hours of the study. Effects on gastric emptying, small bowel transit, and colonic transit were analyzed using Kruskal-Wallis and Wilcoxon rank sum tests. RESULTS: Of 61 patients screened, 40 were eligible and randomized. Two patients withdrew because of adverse events. PRU accelerated overall gastric emptying and small bowel transit. PRU tended to accelerate overall colonic transit with significantly faster overall colonic transit and ascending colon emptying with the 4-mg dose. CONCLUSIONS: PRU accelerates transit through the stomach, small bowel, and colon in patients with constipation unassociated with a rectal evacuation disorder.     

Pan-colonic decrease in interstitial cells of Cajal in patients with slow transit constipation

BACKGROUND: Interstitial cells of Cajal (ICC) are required for normal intestinal motility. ICC are found throughout the human colon and are decreased in the sigmoid colon of patients with slow transit constipation. AIMS: The aims of this study were to determine the normal distribution of ICC within the human colon and to determine if ICC are decreased throughout the colon in slow transit constipation. PATIENTS: The caecum, ascending, transverse, and sigmoid colons from six patients with slow transit constipation and colonic tissue from patients with resected colon cancer were used for this study. METHODS: ICC cells were identified with a polyclonal antibody to c-Kit, serial 0.5 microm sections were obtained by confocal microscopy, and three dimensional software was employed to reconstruct the entire thickness of the colonic muscularis propria and submucosa. RESULTS: ICC were located within both the longitudinal and circular muscle layers. Two networks of ICC were identified, one in the myenteric plexus region and another, less defined network, in the submucosal border. Caecum, ascending colon, transverse colon, and sigmoid colon displayed similar ICC volumes. ICC volume was significantly lower in the slow transit constipation patients across all colonic regions. CONCLUSIONS: The data suggest that ICC distribution is relatively uniform throughout the human colon and that decreased ICC volume is pan-colonic in idiopathic slow transit constipation.     

Biomarkers as a diagnostic tool for irritable bowel syndrome: where are we?

Introduction: Irritable bowel syndrome (IBS) is a common condition in clinical practice. There are currently no objective tests to rule in the disease, but rather tests to rule out other diseases. Biomarkers in IBS may provide the tools needed for diagnosis, prognosis and therapy. These include identification of differences in microbial composition, immune activation, bile acid composition, colonic transit, and alteration in sensation in subgroups of IBS patients.

Areas covered: Studies included in our review were chosen based on a PubMed search for ‘biomarkers’ and ‘IBS’. We have reviewed the literature on biomarkers to appraise their accuracy, validity and whether they are actionable. We have not covered genetic associations as biomarkers in this review.

Expert commentary: There is significant promise in the usefulness of biomarkers for IBS. The most promising actionable biomarkers are markers of changes in bile acid balance, such as elevated bile acid in the stool, and altered colonic transit. However, there is also potential for microbial studies and mucosal proteases as future actionable biomarkers.     

Breath methane associated with slow colonic transit time in children with chronic constipation

OBJECTIVE: This study analyzed the relationship between methane production and colonic transit time in children with chronic constipation. METHODOLOGY: Forty children, from 3 to 13 years of age, suffering from chronic constipation were included. Methane production was defined when the breath methane concentration was greater than 3 ppm. The total and segmental colonic transit times were measured with radio-opaque markers. RESULTS: Soiling was present in 34 (85.0%) of 40 patients with constipation. Methane production was present in 25 of 34 (73.5%) patients with constipation and soiling and only in 1 (16.7%) of 6 with constipation but without soiling (P = 0.014). The medians of total colonic transit time were 80.5 and 61.0 hours, respectively (P = 0.04), in methane and nonmethane producers. Segmental colonic transit times were 17.5 and 10.5 hours, respectively (P = 0.580), in right colon, 29.5 and 10.5 hours (P = 0.001), respectively, in left colon, and 31.5 and 27.0 hours (P = 0.202), respectively, in the rectosigmoid. By the sixth week of treatment, the reduction in the total colonic transit time was greater in patients who had become nonmethane producers. CONCLUSION: The presence of breath methane in children with chronic constipation may suggest the possibility of prolonged colonic transit time.     

Effect of oral erythromycin on colonic transit in patients with idiopathic constipation a pilot study

Erythromycin, a motilin receptor agonist has been shown to have prokinetic effects on the upper gastrointestinal tract and gallbladder. Colonic effects of the drug are controversial, and it is debated whether human colon contains motilin receptors. In this study we evaluated the effects of erythromycin on colonic transit and stool frequency in 11 patients with idiopathic constipation over a 1-month period in an open study. The dose used was 1 g/day for two weeks followed by 500 mg/day for another two weeks. The mean (se) total and segmental colonic transit was measured before and seven days after therapy in seven of these patients. A daily record of stool frequency was maintained in all 11 patients. Erythromycin shortened the total colonic transit from 86.2 (14.6) to 44.8 (8.99) hr (P<0.01); however, segmental transit studies revealed a significant effect (P<0.01) only in the right colon and rectosigmoid region. No significant side effects were observed with short-term therapy. These preliminary results suggest that erythromycin is of therapeutic value in patients with idiopathic constipation.     

Are colonic regular contractile frequency patterns in slow transit constipation a relevant pathophysiological phenomenon?

BACKGROUND: Pathogenesis of slow transit constipation still remains elusive. Some studies have shown several colonic motor abnormalities; however, it is not easy to understand the relative importance of the single ones. AIMS: Since it has been hypothesized that an excess of periodic distal motor activity may be of pathophysiological importance in patients with slow transit constipation, we evaluated regular colonic contractile frequencies in a homogeneous cohort of these patients. PATIENTS: A total of 26 female patients (age range 34 to 67 years) fulfilling the Rome II criteria for constipation entered the study. No patient had evidence of secondary forms of constipation and distal obstruction. METHODS: Twenty-four hour colonic manometric studies were obtained for each patient. Regular contractile patterns (with frequencies ranging from 2 to 8 cycles/min) were calculated for the entire recording period and in single colonic segments. RESULTS: Overall, regular patterns accounted for about 3% of the total colonic motor activity (average 30 min/day per subject), with the 3 cycles/min being the predominant contractile rhythm. Most of this activity was present in the sigmoid colon, accounting for >50% of the total amount of motility, and it was more prevalent than in the descending and transverse colon; no differences were revealed in the descending with respect to the transverse colon. No daily fluctuations of regular contractile activity, nor a cyclic pattern, nor migration between recording points were observed. CONCLUSIONS: Regular colonic frequency patterns are probably of minor pathophysiological importance in slow transit constipation, even in the light of the scant amount of such phenomena previously documented in healthy subjects.     

In patients with slow transit constipation, the pattern of colonic transit delay does not differentiate between those with and without impaired rectal evacuation

BACKGROUND: Severe constipation may be subclassified on the basis of speed of colonic transit and efficacy of rectal evacuation. It is hypothesized that rectal evacuatory disorder (RED) may be associated with a secondary transit delay. OBJECTIVES: To determine whether scintigraphy can discriminate between slow transit constipation (STC) with or without coexistent RED on the basis of progression of isotope throughout the colon and by analyses of specific regions of interest. METHODS: One hundred ninety-six patients with STC (radio-opaque marker study) were subclassified according to results of proctography into those with a RED (STC-RED N = 30) or normal (STC-ONLY N = 41) evacuation. Patients subsequently underwent colonic scintigraphy. Distribution of generalized or left-sided patterns of colonic transit was assessed. Severities of transit delay and regional transit at specific time points were also evaluated. RESULTS: Time-activity curves and severity of global transit delay were similar between groups as were the incidences of generalized and left-sided patterns of delay. Percentage of radioisotope retention in the right colon at 18 h was higher for the STC-ONLY group (P < 0.05), but this was poorly discriminative. No differences were observed for the percentage of radioisotope retained in the left colon at later scans. CONCLUSIONS: Global and regional assessment of colonic transit by scintigraphy failed to discriminate between patients with STC with or without coexistent RED. Thus, RED is not associated with a specific pattern of transit delay and scintigraphy alone cannot predict the presence or absence of RED, knowledge of which is important for management.     

Pelvic motility and response to intraluminal bisacodyl in slow-transit constipation

The resting motility of the pelvic colon was studied in 28 patients with constipation and compared with control subjects and patients with diarrhea. Colonic activity in patients who had been shown to have slow colonic transit was not significantly different from controls. In contrast, activity in patients who complained of constipation but who were found to have normal colonic transit time was increased (P<0.02). The response of the pelvic colon to the introduction of a surface-acting laxative was studied in 18 patients with slow-transit constipation. Eleven patients developed progressive peristaltic waves, while in 7 there was no response. It is possible that the relative inactivity of the colon in the latter group is due to a disorder of the myenteric plexus. If so, the bisacodyl stimulation test may distinguish patients with an abnormal myenteric plexus from those in whom it is normal.Preston was supported by a grant from the St. Mark's Research Foundation.     

Intestinal transit, deoxycholic acid and the cholesterol saturation of bile--three inter-related factors.

There is considerable evidence that the level of deoxycholic acid in the bile influences biliary cholesterol saturation. Deoxycholic acid is formed in the colon and absorbed slowly. Hence changes in colonic transit rate might influence biliary deoxycholic acid and the cholesterol saturation of bile. When 14 constipated subjects took standardised senna tablets for six weeks in a dose sufficient to lower mean whole gut transit time from 134 to 54 hours, deoxycholic acid as a proportion of biliary bile acids fell from 25.9 +/- 8.6 to 17.2 +/- 8.3% (p less than 0.0001) and deoxycholic acid pool measured by isotope dilution fell from 0.64 +/- 0.34 to 0.45 +/- 0.29 g (p less than 0.0001). In those subjects (n = 8) whose bile was initially supersaturated with cholesterol, the saturation index fell from 1.40 +/- 0.22 to 1.20 +/- 0.19 (p = 0.02). Conversely, when 12 normal volunteers took loperamide capsules sufficient to cause symptomatic constipation and to prolong mean transit-time from 48 to 103 hours, the deoxycholic acid pool increased from 0.40 +/- 0.24 to 0.57 +/- 0.17 g (p = 0.008). The percentage deoxycholic acid did not alter significantly, because the estimated total bile acid pool expanded (from 1.98 +/- 0.61 to 2.81 +/- 0.48 g; p less than 0.001), presumably because of loperamide slowing down small bowel transit. Despite this expansion of the bile acid pool, loperamide increased the cholesterol saturation index from 1.10 +/- 0.31 to 1.20 +/- 0.32 (p = 0.01). Changes in colonic transit rate alter the size of the deoxycholic acid pool and bile cholesterol saturation. These findings suggest that constipation or slow colonic transit might increase the chance of supersaturated bile and hence of gall stones.     

改良结肠运输试验在慢性便秘鉴别诊断及治疗中的价值

目的探讨改良结肠运输试验对慢性便秘鉴别诊断及指导治疗中的价值。 方法选取2013年1月至2015年6月,江苏省苏北人民医院胃肠外科便秘专科门诊诊治的慢性便秘患者52例,对52例不同程度排便困难患者和10例健康对照者进行改良结肠运输试验,即在禁食促排便药物72 h后行上消化道钡餐检查,6 h和72 h后再分别拍摄腹部平片,观察钡剂在肠道残留情况,根据检查结果分类并予以相关治疗。 结果所有患者未见胃肠道器质性病变。7 h后,10例健康对照者肠道内无钡剂残留,39例患者钡剂残留在结肠（诊断为慢传输型）,5例患者钡剂残留在直肠（诊断为出口梗阻型）,而8例患者钡剂残留在结直肠内（诊断为混合型）。所有患者予以促结肠动力药物普芦卡必利（2 mg/d）±乳果糖（30 mg/d）治疗,其中1例慢传输型患者、1例出口梗阻型患者和8例混合型患者无效,予以施行腹腔镜下金陵术治愈。 结论改良结肠运输试验对慢性便秘的诊断具有重要价值,有助于不同便秘类型的鉴别及针对性治疗。     

Pharmacodynamic and Clinical Endpoints for Functional Colonic Disorders: Statistical Considerations

Background

Intra- and inter-subject coefficients of variation (COV) of scintigraphic colonic transit (SCT) are well characterized. SCT response to therapy predicts clinical efficacy of experimental medications in lower functional gastrointestinal disorders (FGID).

Aim

To compare COVs for bowel function with pharmacodynamic (PD) colonic transit geometric center (GC) as endpoints in lower FGID studies.

Methods

We evaluated data from placebo arm of 9 phase IIA, parallel-group, clinical trials of PD effects of linaclotide, dexloxiglumide, renzapride, elobixibat, ROSE 010, and chenodeoxycholate in lower FGID with constipation, and pexacerafont, VSL#3, and colesevelam in lower FGID with diarrhea. Patients completed daily diaries for at least 7 days of stool frequency, consistency (7-point Bristol Stool Form Scale), and ease of passage (7-point scale from manual disimpaction to incontinence). Seventeen patients received placebo in 2 separate studies allowing assessment of intra-patient COVs. We calculated sample sizes required to demonstrate a 30 % effect size for colonic transit, stool frequency, consistency and ease of passage for patients with lower FGID with constipation and, separately, diarrhea.

Results

COV_inter from 87 patients and COV_intra from 17 patients are reported. Generally, COV_intra is somewhat greater than COV_inter. The COVs for PD endpoints are lower than for clinical endpoints; however, clinically relevant effects can be identified with modest (~50 %) increases in the sample size using parallel-group design studies.

Conclusion

Phase IIA studies that incorporate clinical and PD endpoints are feasible in lower FGID associated with constipation or diarrhea. Crossover design would require lower sample size for most endpoints compared to parallel-group studies.     

Peptide YY release after colectomy in slow transit constipation

Background: The gut hormone peptide YY is abundant in the colonic mucosa. Circulating PYY inhibits gastrointestinal motility and decreases food intake. The aim was to determine whether colectomy decreases PYY release in patients with slow transit constipation. Methods: Plasma PYY concentrations were measured in 10 patients with slow transit constipation before and 3–24 months after total abdominal colectomy with ileorectal anastomosis, and in 8 healthy controls. A liquid meal was infused intraduodenally to stimulate PYY release. Results: Postprandial PYY significantly (P?Conclusion. Despite removal of a major source of PYY‐secreting cells, colectomy with ileorectal anastomosis does not induce major impairment of PYY release in slow transit constipation.