Upper socioeconomic status is associated with lower Helicobacter pylori infection rate among patients undergoing gastroscopy.

INTRODUCTION: Socioeconomic factors play an important role in the prevalence of Helicobacter pylori (HP) infection. The aim of this study is to investigate HP prevalence among symptomatic patients in the upper socioeconomic segment of the population undergoing gastroscopy in an endemic urban region. METHODOLOGY: Over a 12-month period, data were collected from the first consecutive 1000 patients (500 from university hospital, 500 from community hospital) who had gastroscopy and HP evaluation. RESULTS: Overall, 211/1000 patients (21.1 %) were found to have HP in gastric biopsies. The specificity, sensitivity, positive predictive value, negative predictive value and diagnostic accuracy of rapid urease test were 87.5%, 99.7%, 99%, 96.5%, and 96.9% respectively. Atrophic gastritis, gastric and duodenal ulcers were significantly more common in HP positive patients. Age based distribution of HP prevalence: > 6 decades (15.5%), 3rd-5th decades (26.1%), < 3rd decades (10.4%). CONCLUSION: In an HP endemic country, the prevalence of HP infection among symptomatic patients belonging to the upper socioeconomic segment of the population appears to be markedly lower. The lowest prevalence in young patients is expected to result in future decrease in HP prevalence.

Cryptogenic liver cirrhosis and hepatitis E virus (HEV): Are they related?

INTRODUCTION AND OBJECTIVES: Hepatitis E virus (HEV) is one of the most common causes of acute hepatitis. In recent years, its role in the development of chronic hepatitis and cirrhosis especially in immunosuppressed patients and its wide range of extrahepatic involvement have increased the amount of research on HEV. In this study we aimed to investigate the presence of HEV infection in individuals with cryptogenic cirrhosis. MATERIALS AND METHODS: HEV antibodies were analysed using the Anti HEV enzyme-linked immunosorbent assay (ELISA) kit (anti-HEV ELISA; Diapro Prodiagnostic Bioprobes, Milan, Italy). HEV RNA was isolated with using QIAMP Viral RNA mini kit (QIAGEN, Hilden, Germany). The HEV RNA titre was detected with the Rotor Gene 3000 real time polymerase chain reaction (PCR) system using GenoSen's HEV (Rotor Gene) Quantitative Real Time PCR Kit (Genome Diagnostics Private Limited, the Netherlands). RESULTS: Our study included 21 healthy volunteers (12 males) and 35 cryptogenic cirrhosis patients (19 males). The ages of the patients and the controls were similar (46±12.1 vs. 37.5±9.7years). The mean Child-Pugh score was 8±2.5. The anti HEV immunoglobulin G(IgG) positivity rate was 9.5% and 25.7% in the control and patient groups respectively (p>0.05). HEV RNA positivity was not detected in the control group, but 3 cases (8.6%) in the patient group were positive (p>0.05). The HEV RNA, aspartate aminotransferase (AST) and alanine aminotransferase(ALT) levels for these 3 cases were 326.461copies/mL, 91IU/L and 67IU/L; 480copies/mL, 68IU/L and 36IU/L and 72copies/mL, 42IU/L and 24IU/L respectively. There were positive correlations between HEV RNA levels and AST and ALT levels (p<0.05). CONCLUSIONS: Anti HEVIgG and HEV RNA positivity rates are high in cryptogenic cirrhosis although it is not statistically significant and there is a positive correlation between HEV RNA and aminotransferases.

Which drugs are risk factors for the development of gastroesophageal reflux disease?

Gastroesophageal reflux disease (GERD), which is common in many communities, is associated with structural factors, eating habits, and the use of certain drugs. The use of such drugs can lead to the emergence of GERD and can also exacerbate existing reflux symptoms. These drugs can contribute to GERD by directly causing mucosal damage, by reducing lower esophageal sphincter pressure (LESP), or by affecting esophagogastric motility. In this article, we report our investigation of the relationships between GERD and medications within the scope of the "Turkish GERD Consensus Group." For the medication groups for which sufficient data were obtained (Figure 1), a systematic literature review in English was conducted using the keywords "gastroesophageal reflux" [MeSH Terms] and "anti-inflammatory agents, non-steroidal" [MeSH Terms], "gastroesophageal reflux" [MeSH Terms] and "acetylsalicylic acid" [MeSH Terms], "gastroesophageal reflux" [All Fields] and "estrogenic agents" [All Fields], "gastroesophageal reflux" [All Fields] and "progesterones" [All Fields], "gastroesophageal reflux" [All Fields] and "hormone replacement therapy" [All Fields], "gastroesophageal reflux" [MeSH Terms] and "diphosphonates" [MeSH Terms] OR "diphosphonates" [All Fields], "calcium channel blockers" [MeSH Terms] and "gastroesophageal reflux" [MeSH Terms], "gastroesophageal reflux" [MeSH Terms] and "nitrates" [MeSH Terms], "gastroesophageal reflux" [MeSH Terms] and "antidepressive agents" [MeSH Terms], "gastroesophageal reflux" [MeSH Terms] and "benzodiazepines" [MeSH Terms] and "hypnotic drugs" [MeSH Terms], "gastroesophageal reflux" [MeSH Terms] and "cholinergic antagonists" [MeSH Terms], "gastroesophageal reflux" [MeSH Terms] and "theophylline" [MeSH Terms], and "gastroesophageal reflux [MeSH Terms] AND "anti-asthmatic agents" [MeSH Terms]. The studies were analyzed and the results are presented here.

Gastroesophageal reflux disease and the relationship with Helicobacter pylori.

After Helicobacter pylori was identified, and its relationship with peptic ulcer disease was exactly shown, the relationship of this bacterium with gastroesophageal reflux disease (GERD) gained momentum and discussions continue to this day. We reviewed the literature for the relationship between H. pylori and GERD. According to the existing data, there is no relationship between GERD and H. pylori presence. Successful eradication therapy does not have an impact on the emergence or exacerbation of GERD. However Barrett's esophagus and esophageal adenocarcinoma are less frequent, especially in the presence of CagA positive H. pylori infections. Long-term use of proton pump inhibitor (PPI) may have an impact on the development of atrophy and/or intestinal metaplasia in H. pylori positive patients; therefore, H. pylori eradication is recommended in patients that should use long-term PPI. As a conclusion, H. pylori screening and the eradication decision should be independent of GERD, except for patients that will use long-term PPI.

Vildagliptin-induced acute pancreatitis without enzyme elevation.

We describe 2 patients with diabetes mellitus, presenting with upper abdominal pain. Although imaging findings were consistent with acute pancreatitis (AP), serum amylase and lipase levels were within normal limits. In both the cases, the only identifiable diagnostic culprit was vildagliptin. This is the first reported case of vildagliptin causing AP clinically and radiographically without elevated serum pancreatic enzymes. In conclusion, even when serum amylase and lipase levels are normal, AP should be kept in mind when making a differential diagnosis of patients with diabetes mellitus who present with abdominal pain and take dipeptidyl peptidase-4 (DPP-4) inhibitors.

Mutations in RAD21 disrupt regulation of APOB in patients with chronic intestinal pseudo-obstruction.

BACKGROUND & AIMS: Chronic intestinal pseudo-obstruction (CIPO) is characterized by severe intestinal dysmotility that mimics a mechanical subocclusion with no evidence of gut obstruction. We searched for genetic variants associated with CIPO to increase our understanding of its pathogenesis and to identify potential biomarkers. METHODS: We performed whole-exome sequencing of genomic DNA from patients with familial CIPO syndrome. Blood and lymphoblastoid cells were collected from patients and controls (individuals without CIPO); levels of messenger RNA (mRNA) and proteins were analyzed by quantitative reverse-transcription polymerase chain reaction, immunoblot, and mobility shift assays. Complementary DNAs were transfected into HEK293 cells. Expression of rad21 was suppressed in zebrafish embryos using a splice-blocking morpholino (rad21a). Gut tissues were collected and analyzed. RESULTS: We identified a homozygous mutation (p.622, encodes Ala>Thr) in RAD21 in patients from a consanguineous family with CIPO. Expression of RUNX1, a target of RAD21, was reduced in cells from patients with CIPO compared with controls. In zebrafish, suppression of rad21a reduced expression of runx1; this phenotype was corrected by injection of human RAD21 mRNA, but not with the mRNA from the mutated p.622 allele. rad21a Morpholino zebrafish had delayed intestinal transit and greatly reduced numbers of enteric neurons, similar to patients with CIPO. This defect was greater in zebrafish with suppressed expression of ret and rad21, indicating their interaction in the regulation of gut neurogenesis. The promoter region of APOB bound RAD21 but not RAD21 p.622 Ala>Thr; expression of wild-type RAD21 in HEK293 cells repressed expression of APOB, compared with control vector. The gut-specific isoform of APOB (APOB48) is overexpressed in sera from patients with CIPO who carry the RAD21 mutation. APOB48 also is overexpressed in sporadic CIPO in sera and gut biopsy specimens. CONCLUSIONS: Some patients with CIPO carry mutations in RAD21 that disrupt the ability of its product to regulate genes such as RUNX1 and APOB. Reduced expression of rad21 in zebrafish, and dysregulation of these target genes, disrupts intestinal transit and the development of enteric neurons.

Is It Barrett's Esophagus or Gastric Heterotopia?

Columnar epithelium in the distal part of the esophagus is generally related to Barrett's esophagus. Barrett's esophagus is a well-known premalignant lesion for adenocarcinoma of the esophagus. Therefore, its diagnosis and surveillance are important. Columnar epithelium in the esophagus other than Barrett's esophagus can be gastric heterotopia, which generally takes place in the upper part of the esophagus and is named inlet patch. The presence of gastric metaplasia in the distal part of the esophagus is rare and can cause misdiagnosis. Therefore, its differentiation from Barrett's esophagus is important. Here we present a case of gastric heterotopia located in the distal part of the esophagus that caused reflux-like symptoms and needed differentiation from Barrett's esophagus.

Eosinophilic jejunitis presenting as intractable abdominal pain.

Eosinophilic gastroenteritis is an uncommon disease characterized by eosinophilic infiltration of the gastrointestinal tract. The clinical manifestations are related to the layer(s) and extent of the bowel involved. In this paper, we present a case of intractable abdominal pain caused by jejunal submucosal eosinophilic infiltration without mucosal involvement, diagnosed by deep endoscopic biopsies. The patient was successfully treated with steroids without need for surgery for diagnosis or therapy.

Association of the MEFV gene variations with inflammatory bowel disease in Turkey.

BACKGROUND: Association of NOD2 (CARD15) gene mutations with inflammatory bowel diseases (IBD) is well known. We herein aimed to investigate the role of familial Mediterranean fever-associated MEFV variations in IBD patients as additional regional-specific risk factor. STUDY: One hundred thirty-seven (78 female, 56.9%) IBD patients [62 Crohn's disease (CD), 75 ulcerative colitis (UC)] were enrolled into the study. The diagnosis of all patients was confirmed by colonoscopy, histopathology, and the clinical findings. One hundred one healthy donors' samples were used as healthy controls. All patients were genotyped for the most common E148Q, M608I, M694V, and V726A variations of the MEFV and R702W, G908R, and 1007fs of the NOD2. RESULTS: The overall MEFV variation frequency was found to be higher in the IBD (25.5%) patients (28% in UC, 22.6% in CD) compared with controls (9.9%, P=0.006). This association was stronger with the penetrant exon 10 variations (M694V, M680I, V726A; odds ratio =4.5, P=0.001). Contribution of M694V was higher compared with the other variations (14.5% in CD, 17.3% in UC and 3% in controls, odds ratio =6.039, 95% confidence intervals, 1.7-20.7, P=0.002). The overall frequency of 3 NOD2 variants in the IBD group was not different from that of controls. CONCLUSIONS: The results of this study suggest that the MEFV variations may be an additional susceptibility factor for IBD in certain parts of the world where the carrier rate is high, and the genetic background of the IBD patients may show regional changes.

Variability in the management of nonvariceal upper gastrointestinal bleeding in Europe: an observational study.

INTRODUCTION: Despite recent advances in endoscopic and pharmacological management, nonvariceal upper gastrointestinal bleeding (NVUGIB) is still associated with considerable mortality and morbidity that vary between countries. The European Survey of Nonvariceal Upper Gastrointestinal Bleeding (ENERGiB) reported clinical outcomes across Europe (Belgium, Greece, Italy, Norway, Portugal, Spain, and Turkey) and evaluated management strategies in a "real-world" European setting. This article presents the differences in clinical management strategies among countries participating in ENERGiB. METHODS: Adult patients consecutively presenting with overt NVUGIB at 123 participating hospitals over a 2-month period were included. Data relevant to the initial NVUGIB episode and for up to 30 days afterwards were collected retrospectively from patient medical records. RESULTS: The number of evaluable patients was 2,660; patient demographics and clinical characteristics were similar across countries. There was wide between-country variability in the area and speciality of the NVUGIB management team and unit transfer rates after the initial hospital assessment. The mean time from admission to endoscopy was <1 day only in Italy and Spain. Wide variation in the use of preendoscopy (35.0-88.7%) and relatively consistent (86.5-96.0%) postendoscopic pharmacological therapy rates were observed. There was substantial by-country variability in the rate of therapeutic procedures performed during endoscopy (24.9-47.6%). NVUGIB-related healthcare resource consumption was high and variable (days hospitalized, mean 5.4-8.7 days; number of endoscopies during hospitalization, mean 1.1-1.7). CONCLUSIONS: ENERGiB demonstrates that there are substantial differences in the management of patients with acute NVUGIB episodes across Europe, and that in many cases the guideline recommendations for the management of NVUGIB are not being followed.

An observational European study on clinical outcomes associated with current management strategies for non-variceal upper gastrointestinal bleeding (ENERGIB-Turkey).

BACKGROUND/AIMS: This observational, retrospective cohort study assessed outcomes of the current management strategies for nonvariceal upper gastrointestinal bleeding in several European countries (Belgium, Greece, Italy, Norway, Portugal, Spain, and Turkey) (NCT00797641; ENERGIB). MATERIALS AND METHODS: Turkey contributed 23 sites to this study. Adult patients (≥18 years old) consecutively admitted to hospital and who underwent endoscopy for overt non-variceal upper gastrointestinal bleeding (hematemesis, melena or hematochezia, with other clinical/laboratory evidence of acute upper GI blood loss) were included in the study. Data were collected from patient medical records regarding bleeding continuation, re-bleeding, pharmacological treatment, surgery, and mortality during a 30-day follow-up period. RESULTS: A total of 423 patients (67.4% men; mean age: 57.8 ± 18.9 years) were enrolled in the Turkish study centers, of whom 96.2% were admitted to hospital with acute non-variceal upper gastrointestinal bleeding. At admission, the most common symptom was melena (76.1%); 28.6% of patients were taking aspirin, 19.9% were on non-steroidal anti-inflammatory drugs, and 7.3% were on proton pump inhibitors. The most common diagnoses were duodenal (45.2%) and gastric (27.7%) ulcers and gastritis/gastric erosions (26.2%). Patients were most often managed in general medical wards (45.4%). A gastrointestinal team was in charge of treatment in 64.8% of cases. Therapeutic procedures were performed in 32.4% of patients during endoscopy. After the endoscopy, most patients (94.6%) received proton pump inhibitors. Mean (SD) hospital stay was 5.36 ± 4.91 days. The cumulative proportions of continued bleeding/re-bleeding, complications and mortality within 30 days of the non-variceal upper gastrointestinal bleeding episode were 9.0%, 5.7% and 2.8%, respectively. In the Turkish sub-group of patients, the significant risk factors for bleeding continuation or re-bleeding were age >65 years, presentation with hematemesis or shock/syncope, and the diagnosis of duodenal ulcer. The risk of clinical complications after non-variceal upper gastrointestinal bleeding was higher in female patients older than 65 years, in patients with comorbidities, and in patients presenting with shock/syncope, and also according to time to endoscopy. The use of aspirin, non-steroidal anti-inflammatory drugs or warfarin at baseline was negatively associated with the development of bleeding or clinical complications. The risk of death within 30 days after non-variceal upper gastrointestinal bleeding was significantly higher in patients older than 65 years and in those receiving transfusions other than intravenous fluid or red blood cells within 12 hours of presentation. CONCLUSIONS: According to the survey results, non-variceal upper gastrointestinal bleeding in Turkey varies from that in other European countries in a number of aspects. These differences could be associated with a younger population and Helicobacter pylori incidence. Despite the diminishing need for surgical intervention and mortality rates for non-variceal upper gastrointestinal bleeding, as is the case in other European countries, non-variceal upper gastrointestinal bleeding remains a serious problem.

Prevalence and demographic determinants of gastroesophageal reflux disease (GERD) in the Turkish general population: a population-based cross-sectional study.

BACKGROUND/AIMS: We aimed to establish the prevalence and demographic determinants of gastroesophageal reflux disease in the Turkish general population using the Turkish version of the gastroesophageal reflux disease questionnaire. MATERIAL AND METHODS: A total of 8143 volunteers (mean age: 38.5 (13.3) years; 52.3% males) were included in this cross-sectional questionnaire study conducted via face-to-face administration of the questionnaire forms including items on sociodemographic features, past history of gastric disorders, gastroesophageal reflux disease, the influence of reflux symptoms on patients' lives, physician visits, diagnostic tests, and reflux medications. RESULTS: A past history of gastric symptoms was reported in half of the population. More female participants (p<0.001) had a past history of gastric symptoms that yielded a previous diagnosis of gastroesophageal reflux disease in 19.1% of the population. The likelihood of gastroesophageal reflux disease was low in the majority (75.3%) of the subjects evaluated. Gastroesophageal reflux disease with an inconveniencing or disrupting impact on the patient's life was present in 17.9% and 6.8% of the population. Total gastroesophageal reflux disease-questionnaire scores and reflux prevalence were higher in older age groups (p<0.001). Females were more likely to have gastroesophageal reflux disease prevalence based on reflux symptoms. The impact of gastroesophageal reflux disease on sleep and psychological/emotional well-being was more pronounced in older and female patients, whereas the impact on eating/drinking behaviors and physical-social activities was more marked among females independent of their age (p<0.001). Reflux prevalence was higher in subjects from East Anatolia, Central Anatolia, Mediterranean, and Black Sea regions of Turkey (p<0.001 for each). CONCLUSIONS: Prevalence and demographic determinants of gastroesophageal reflux disease are compatible with the profile of the disease in the other Western populations, with a predilection for females and older individuals.

Etiological factors of duodenal and gastric ulcers.

BACKGROUND/AIMS: We aimed to determine the etiology of patients with duodenal and gastric ulcers. METHODS: 140 patients diagnosed with peptic ulcer between April 2002-2009 were enrolled in this prospective study. Two biopsy specimens were collected from the antrum and corpus for histology and one for rapid urease testing, and stool samples were analyzed for Helicobacter pylori antigen. Serum calcium and gastrin levels were also analyzed. RESULTS: 82 (58%) patients were male, with a median age of 47.70±15.03 years (range: 16-92). The ulcer was located in the duodenum in 96 patients, stomach in 40, and both duodenum and stomach in 4. The rates of patients positive for Helicobacter pylori antigen in stool, positive in urease testing and positive for Helicobacter pylori presence in antral and corpus samples were 48%, 52%, 67%, and 60%, respectively. 107 (76%) patients were positive for Helicobacter pylori in one of the test methods. 64 (46%) patients had a history of nonsteroidal antiinflammatory drug use within the last month. Mean levels of calcium and gastrin were 9.29±0.40 (7.90-10.20) and 73.96±89.88 (12.86-562.50), respectively. Gastrin level was correlated to inflammatory activity (p<0.05). 19 (13.6%) of the patients were negative for Helicobacter pylori, nonsteroidal anti- inflammatory drug use and hypersecretory illness, and were classified as idiopathic. CONCLUSIONS: The most common cause of duodenal and gastric ulcer was Helicobacter pylori, and it was responsible for three-fourths of the cases. About half of the patients had a history of nonsteroidal antiinflammatory drug use, and nonsteroidal antiinflammatory drug and Helicobacter pylori were both responsible for the ulcer in three-fourths of these patients. In about one-tenth of the patients, nonsteroidal antiinflammatory drug use was the cause of ulcer alone, and about one-tenth of the ulcers were classified as idiopathic.

Does Cholecystectomy Increase the Esophageal Alkaline Reflux? Evaluation by Impedance-pH Technique.

BACKGROUND/AIMS: The aim of this study is to investigate the reflux patterns in patients with galbladder stone and the change of reflux patterns after cholecystectomy in such patients. METHODS: Fourteen patients with cholecystolithiasis and a control group including 10 healthy control subjects were enrolled in this prospective study. Demographical findings, reflux symptom score scale and 24-hour impedance pH values of the 14 cholecystolithiasis cases and the control group were evaluated. The impedance pH study was repeated 3 months after cholecystectomy. RESULTS: Age, gender, and BMI were not different between the two groups. Total and supine weakly alkaline reflux time (%) (1.0 vs 22.5, P = 0.028; 201.85 vs 9.65, P = 0.012), the longest episodes of total, upright and supine weakly alkaline reflux mediums (11 vs 2, P = 0.025; 8.5 vs 1.0, P = 0.035; 3 vs 0, P = 0.027), total and supine weakly alkaline reflux time in minutes (287.35 vs 75.10, P = 0.022; 62.5 vs 1.4, P = 0.017), the number of alkaline reflux episodes (162.5 vs 72.5, P = 0.022) were decreased with statistical significance. No statistically significant difference was found in the comparison of symptoms between the subjects in the control group and the patients with cholecystolithiasis, in preoperative, postoperative and postcholecystectomy status. CONCLUSIONS: Significant reflux symptoms did not occur after cholecystectomy. Post cholecystectomy weakly alkaline reflux was decreased, but it was determined that acid reflux increased after cholecystectomy by impedance pH-metry in the study group.

Second-line levofloxacin-based triple therapy's efficiency for Helicobacter pylori eradication in patients with peptic ulcer.

OBJECTIVES: First-line standard eradication efficacy with lansoprazole, amoxicillin and clarithromycin regressed over 10 years. The aim of this study was to evaluate the efficacy and tolerability of a levofloxacin-based regimen in patients with peptic ulcer after failure of the standard first-line H.pylori eradication therapy in a country with a high rate of infection. METHODS: A total of 91 peptic ulcer patients who were diagnosed H.pylori positive proven by rapid urease test and histology between November 2005 to March 2008 were given lansoprazole 30 mg bid, amoxicillin 1 g bid and clarithromycin 500 mg bid (LAC) for 14 days. After three months from the first line eradication treatment omeprazole 20 mg bid, levofloxacin 500 mg bid, amoxicillin 1 g bid (OLA) 7 day treatment regimen was recommended as a second-line therapy for 37 patients who failed at first-line standard triple therapy. RESULTS: Eradication rates for LAC regimen were found to be 57.14% (52/91) for intention to treat and 58.42% (52/89) for per protocol analysis. Eradication rates for OLA regimen were found to be 37.83% (14/37) for ITT and 41.17% (14/34) for PP analysis. CONCLUSION: OLA regimen eradication rate was successful only in 40% of patients who failed in the first-line eradication. New eradication treatment strategies must be performed, at least in Turkey.

Effect of proton pump inhibitor (PPI) treatment in obstructive sleep apnea syndrome: an esophageal impedance-pHmetry study.

BACKGROUND/AIMS: There is an increasing interest for a link between gastroesophageal reflux (GER) and obstructive sleep apnea syndrome (OSAS). There is no study in the literature which examines the relationship between OSAS and esophageal functions in adults with impedance. We first evaluated the role of reflux in OSAS with simultaneous polysomnography and impedance-pHmetry and then investigated whether the effect of proton pump inhibitor (PPI) treatment changes in these parameters. METHODOLOGY: Twenty two OSAS patients who had applied to sleep laboratory between September 2007 and May 2008 were consecutively enrolled to the study. Twenty four hours esophageal impedance study was performed during polysomnographic recording. At least 50% of all apneas in patients must proceed with a reflux event in 2 minute intervals in order to be considered reflux related apnea patient. RESULTS: Pathologic reflux episodes were determined in 20 patients (8 were weakly acidic, 12 were acidic). Reflux dependent apnea was found in 6 patients. There was endoscopically esophagitis in all reflux related apnea patients. There was a negative correlation between initial mean SaO2 and gas reflux events at night (p=0.004, r =-0.588) and mixed reflux events at night (p=0.02, r=0.493). There was a statistically significant regression of AHI (apnea hypopnea index) after 3-months PPI treatment (p=0.012). CONCLUSIONS: Reflux may trigger apnea in some of the OSAS patients. Therefore, each OSAS patient must be inquired about esophageal and extraesophageal symptoms of reflux.

Postprandial platelet-poor plasma 5-hydroxytryptamine concentrations during diarrhea and constipation periods of alternatingtype irritable bowel syndrome patients.

BACKGROUND/AIMS: Our aim was to measure concentrations of platelet-poor plasma 5-hydroxytryptamine and to assess any relationship with gastrointestinal symptomatology under fasting and fed conditions in alternating-type irritable bowel syndrome during both constipation and diarrhea periods separately. Results of the two periods were compared with each other as well as with the results of the controls. METHODS: Nine patients with alternating diarrhea and constipation symptoms and 9 controls were enrolled. Serial plasma 5-hydroxytryptamine was measured for 1 hour under fasting and for 3 hour after a standard carbohydrate meal. Patients underwent the same measurements during constipation and diarrhea periods separately. Serum 5-hydroxytryptamine concentrations were determined by high-performance liquid chromatography. Symptomatology was assessed throughout the study. RESULTS: Patients exhibited higher concentrations of platelet-poor plasma 5-hydroxytryptamine under fed conditions during diarrhea, especially at postprandial 30 minutes (p<0.05) compared with concentrations during constipation. Increases in postprandial plasma 5-hydroxytryptamine concentrations relative to fasting concentrations were also significantly higher during the diarrhea period than during constipation and in controls (p<0.05). Although there was no significant correlation between plasma 5-hydroxytryptamine concentrations and symptom scores, patients had worse postprandial symptomatology during diarrhea compared with controls (p<0.05). CONCLUSIONS: Platelet-poor plasma 5-hydroxytryptamine concentrations after meal ingestion differ between constipation and diarrhea periods in alternating-type irritable bowel syndrome. Postprandial symptomatology is also more prominent during diarrhea. These results suggest that differences in plasma levels of serotonin between diarrhea and constipation may underlie the pathogenesis of alternating-type irritable bowel syndrome and could be involved in some aspects of symptomatology.