Lactose malabsorption and intolerance: What should be the best clinical management?

Lactose malabsorption (LM) is the incomplete hydrolysis of lactose due to lactase deficiency, which may occur as a primary disorder or secondary to other intestinal diseases. Primary adult-type hypolactasia is an autosomal recessive condition resulting from the physiological decline of lactase activity. Different methods have been used to diagnose LM. Lactose breath test represents the most reliable technique. A recent consensus conference has proposed the more physiological dosage of 25 g of lactose and a standardized procedure for breath testing. Recently a new genetic test, based on C/T13910 polymorphism, has been proposed for the diagnosis of adult-type hypolactasia, complementing the role of breath testing. LM represents a wellknown cause of abdominal symptoms although only some lactose malabsorbers are also intolerants. Diagnosing lactose intolerance is not straightforward. Many non-malabsorber subjects diagnose themselves as being lactose intolerant. Blind lactose challenge studies should be recommended to obtain objective results. Besides several studies indicate that subjects with lactose intolerance can ingest up to 15 g of lactose with no or minor symptoms. Therefore a therapeutic strategy consists of a lactose restricted diet avoiding the nutritional disadvantages of reduced calcium and vitamin intake. Various pharmacological options are also available. Unfortunately there is insufficient evidence that these therapies are effective. Further double-blind studies are needed to demonstrate treatment effectiveness in lactose intolerance.     

Breath test for differential diagnosis between small intestinal bacterial overgrowth and irritable bowel disease： An observation on non-absorbable antibiotics

AIM： To estimate the prevalence of small intestine bacterial overgrowth （SIBO） among patients with an earlier diagnosis of irritable bowel disease （IBS） in our geographical area, and to collect information on the use of locally acting non-absorbable antibiotics in the management of SIBO. METHODS： A non-interventional study was conducted in 73 consecutive patients with a symptom-based diagnosis.. RESULTS： When the patients underwent a ＂breath test＂, 33 （45.2%） showed the presence of a SIBO. Arcer treatment with rifaximin 1200 mg/d for seven days in 32 patients, 19 （59.4%） showed a negative ＂breath test＂ one week later as well as a significant reduction of symptoms, thus confirming the relationship between SIBO and many of the symptoms claimed by patients. In the other 13 patients, ＂breath test＂ remained positive, and a further cycle of treatment with ciprofloxacin 500 mg/d was given for 7 additional days, resulting in a negative ＂breath test＂ in one patient only. CONCLUSION： （1） about half of the patients with a symptomatic diagnosis of IBS have actually SIBO, which is responsible for most of the symptoms attributed to IBS; （2） only a ＂breath test＂ with lactulose （or with glucose in subjects with an intolerance to lactose） can provide a differential diagnosis between IBS and SIBO, with almost identical symptoms; and （3） the use of non-absorbable antibiotics may be useful to reduce the degree of SIBO and related symptoms; it must be accompanied, however, by the correction of the wrong alimentary habits underlying SIBO.     

Management and treatment of lactose malabsorption

Lactose malabsorption is a very common condition characterized by intestinal lactase deficiency. Primary lactose malabsorption is an inherited deficit present in the majority of the world's population, while secondary hypolactasia can be the consequence of an intestinal disease. The presence of malabsorbed lactose in the colonic lumen causes gastrointestinal symptoms. The condition is known as lactose intolerance. In patients with lactase nonpersistence, treatment should be considered exclusively if intolerance symptoms are present. In the absence of guidelines, the common therapeutic approach tends to exclude milk and dairy products from the diet. However, this strategy may have serious nutritional disadvantages. Several studies have been carried out to find alternative approaches, such as exogenousβ-galactosidase, yogurt and probiotics for their bacterial lactase activity, pharmacological and non pharmacological strategies that can prolong contact time between enzyme and substrate delaying gastrointestinal transit time, and chronic lactose ingestion to enhance colonic adaptation. In this review the usefulness of these approaches is discussed and a therapeutic management with a flow chart is proposed.     

Early prediction of major depression in chronic hepatitis C patients during peg-interferon alpha-2b treatment by assessment of vegetative-depressive symptoms after four weeks

AIM： To study the predictive value of the vegetativedepressive symptoms of the Zung Depression Rating Scale for the occurrence of depression during treatment with peg-interferon α-2b of chronic hepatitis C （CHC） patients. METHODS： The predictive value of vegetativedepressive symptoms at 4 wk of treatment for the occurrence of a subsequent diagnosis of major depressive disorder （MDD） was studied in CHC patients infected after substance use in a prospective, multicenter treatment trial in Belgium. The presence of vegetative-depressive symptoms was assessed using the Zung Scale before and 4 wk after the start of antiviral treatment. RESULTS： Out of 49 eligible patients, 19 （39%） developed MDD. The area under the ROC curve of the vegetative Zung subscale was 0.73, P = 0.004. Thesensitivity at a cut-point of 〉 15/35 was 95% （95% CI： 74-100）. The positive predictive value equalled 44% （95% CI： 29-60）. CONCLUSION： In this group of Belgian CHC patients infected after substance use, antiviral treatment caused a considerable risk of depression. Seven vegetativedepressive symptoms of the Zung scale at wk 4 of treatment predicted 95% of all emerging depressions, at a price of 56% false positive test results.     

Early diagnosis and prediction of severity in acute pancreatitis using the urine trypsinogen-2 dipstick test： A prospective study

AIM： To evaluate the use of the trypsinogen-2 dipstick （Actim Pancreatitis） test for early diagnosis and prediction of severity in acute pancreatitis （AP）. METHODS： Ninety-two patients with AP were included in this study. The control group was 25 patients who had acute abdominal pain from non-pancreatic causes. Urine trypsinogen-2 dipstick test （UTDT） and conventional diagnostic tests were performed in all patients. Patients were divided by the Atlanta classification into two groups as having mild or severe pancreatitis. RESULTS： UTDT was positive in 87 （94.6%） of the AP patients and in two （8%） controls （P 〈 0.05）. Positive UTDT was found in 61 （92.4%） of 66 （71.7%） patients with mild pancreatitis and in all （100%） of the 26 （28.3%） with severe pancreatitis （P 〉 0.05）. UTDT positivity lasted longer in severe pancreatitis compared with that in mild pancreatitis （6.2 ＋ 2.5 d vs 2.0 ＋ 1.43 d, P 〈 0.05）. The sensitivity, specificity, positive predictive value, negative predictive value （NPV）, positive likelihood ratio （PLR） and negative likelihood ratio （NLR） of UTDT were 91%, 72%, 96.6%, 70.4%, 3.4 and 0.1, respectively. CONCLUSION： UTDT is a simple, rapid and reliable method for use on admission. It has high specificity and low NLR for early diagnosis and prediction of severity in AP. However, its relatively low NPV does not allow trypsinogen-2 dipstick test to be a stand-alone tool for diagnosis of acute pancreatitis; the use of other conventional diagnostic tools remains a requirement.     

Magnetic resonance cholangiopancreatography for the detection of pancreatic duct stones in patients with chronic pancreatitis

AIM： To assess the role of magnetic resonance cholangiopancreatography （MRCP） in detection of pancreatic duct stones （PDS） in patients with chronic pancreatitis （CP）. METHODS： Clinical data of 78 CP patients who were treated at the First Affiliated Hospital of Xi＇an Jiaotong University （China） between January 2004 and July 2008 were retrospectively analyzed. A predictive model of pancreatic duct stones was established through logistic regression and its effectiveness was verified. Among these patients, MRCP was performed in 60 patients who served as a control group, while 44 patients with a higher predictive value than the entry threshold of the predictive model served as an experimental group. RESULTS： The positive rate of PDS in the 78 patients with CP was 19.2% （15/78）. The predictive entry threshold of the predictive model was 5% （P 〈 0.05）. The possibility of existence of PDS could be predicted according to the following 4 indexes： gastrointestinal symptoms, intermittent abdominal pain, diabetes mellitus （DM）/impaired glucose tolerance （IGT） and positive B-mode ultrasound results. The incidence of PDS in the experimental group was higher than that in the control group （P 〈 0.05）.CONCLUSION： MRCP is strongly suggested for the detection of PDS in patients with gastrointestinal symptoms, intermittent abdominal pain, DM/IGT and positive B-mode ultrasound results.     

Significance of antineutrophil cytoplasmic antibody in adult patients with Henoch-Schönlein purpura presenting mainly with gastrointestinal symptoms

AIM： To test the clinical significance of antineutrophil cytoplasmic antibody （ANCA） in evaluation of adult Henoch-Schonlein purpura （HSP） patients presenting mainly with abdominal symptoms. METHODS： Twenty-eight consecutive HSP patients who presented predominantly with abdominal symptoms were enrolled in this study. Control subjects included 27 ageand sex-matched patients with peptic ulcer disease, colon cancer, acute gastroenteritis, irritable bowel syndrome and colonic polyps. ANCA was measured by indirect immunofluorescence （IIF） in all patients, and follow-up ELISA was performed in patients with positive IIF tests. RESULTS： ANCA was detected in 9 HSP patients by IIF （2 were positive for c-ANCA and 7 were positive for p-ANCA）. No ANCA was found in the control group. The sensitivity and specificity of a positive ANCA test （either c- or p-ANCA） were 32.1% and 100% respectively. Only one out of the 9 patients with positive ANCA by IIF had positive ANCA by ELISA and the antigen was myeloperoxidase （MPO）. The patients positive for ANCA had higher HSP clinical scores, and were more likely to have renal function impairment. Patients with late purpura development were also associated with more severe clinical manifestations. CONCLUSION： A positive ANCA test is associated with more severe symptoms in HSP. After inflammatory bowel disease is excluded, a positive ANCA test provides a clue to the diagnosis of HSP presenting predominantly with abdominal symptoms.     

Seventy-five gram glucose tolerance test to assess carbohydrate malabsorption and small bowel bacterial overgrowth

AIM: To investigate non-invasively the incidence of absorption of carbohydrates in diabetic patients during an oral glucose tolerance test (OGTT) and to determine whether malabsorption may be associated with insulin secretion and insulin resistance. METHODS: A standard 75-g OGTT was performed in 82 diabetic patients. The patients received 75 g of anhydrous glucose in 225 mL of water after an overnight fasting and breath samples were collected at baseline and up to 120 min after ingestion. Breath hydrogen and methane concentrations were measured. Blood glucose and serum insulin concentrations were measured before ingestion and at 30, 60, 90, 120 min post-ingestion. RESULTS: When carbohydrate malabsorption was defined as subjects with an increase of at least 10 ppm (parts per million) in hydrogen or methane excretion within a 2-h period, 28 (34%) had carbohydrate malabsorption. According to the result of increased breath test, 21 (75%) patients were classified as small bowel bacterial overgrowth and 7 (25%) as glucose malabsorption. Patients with carbohydrate malabsorption were older and had poor glycemic control as compared with those without carbohydrate malabsorption. The HOMA value, the sum of serum insulin during the test and the Ainsulin/Aglucose ratio were greater in patients with carbohydrate malabsorption. CONCLUSION: Insulin resistance may be overestimated by using these markers if the patient has carbohydrate malabsorption, or that carbohydrate malabsorption may be present prior to the development of insulin resistance. Hence carbohydrate malabsorption should be taken into account for estimating insulin resistance andβ-cell function.     

Early prediction of major depression in chronic hepatitis C patients during peg-interferon α-2b treatment by assessment of vegetative-depressive symptoms after four weeks

AIM: To study the predictive value of the vegetative- depressive symptoms of the Zung Depression Rating Scale for the occurrence of depression during treatment with peg-interferon α-2b of chronic hepatitis C (CHC) patients. METHODS: The predictive value of vegetative- depressive symptoms at 4 wk of treatment for the occurrence of a subsequent diagnosis of major depressive disorder (MDD) was studied in CHC patients infected after substance use in a prospective, multi- center treatment trial in Belgium. The presence of vegetative-depressive symptoms was assessed using the Zung Scale before and 4 wk after the start of antiviral treatment. RESULTS: Out of 49 eligible patients, 19 (39%) developed MDD. The area under the ROC curve of the vegetative Zung subscale was 0.73, P = 0.004. The sensitivity at a cut-point of > 15/35 was 95% (95% CI: 74-100). The positive predictive value equalled 44% (95% CI: 29-60). CONCLUSION: In this group of Belgian CHC patients infected after substance use, antiviral treatment caused a considerable risk of depression. Seven vegetativedepressive symptoms of the Zung scale at wk 4 of treatment predicted 95% of all emerging depressions, at a price of 56% false positive test results.     

Long-term symptom development of functional bowel disease and the effects of lactose-restricted diet on the symptoms

正Objective To explore the long-term symptom development in functional bowel disorders(FBD)and the effects of lactose-restricted diet on the symptoms.Methods From January 2008 to December 2010,805patients with FBD were included.Among them 245patients who completed lactose hydrogen breath test and     

Clinical value of rapid urine trypsinogen-2 test strip, urinary trypsinogen activation peptide, and serum and urinary activation peptide of carboxypeptidase B in acute pancreatitis

AIM: To assess the usefulness of urinary trypsinogen-2 test strip, urinary trypsinogen activation peptide (TAP), and serum and urine concentrations of the activation peptide of carboxypeptidase B (CAPAP) in the diagnosis of acute pancreatitis. METHODS: Patients with acute abdominal pain and hospitalized within 24 h after the onset of symptoms were prospectively studied. Urinary trypsinogen-2 was considered positive when a clear blue line was observed (detection limit 50 μg/L). Urinary TAP was measured using a quantitative solid-phase ELISA, and serum and urinary CAPAP by a radioimmunoassay method. RESULTS: Acute abdominal pain was due to acute pancreatitis in 50 patients and turned out to be extrapancreatic in origin in 22 patients. Patients with acute pancreatitis showed significantly higher median levels of serum and urinary CAPAP levels, as well as amylase and lipase than extrapancreatic controls. Median TAP levels were similar in both groups. The urinary trypsinogen-2 test strip was positive in 68% of patients with acute pancreatitis and 13.6% in extrapancreatic controls (P<0.01). Urinary CAPAP was the most reliable test for the diagnosis of acute pancreatitis (sensitivity 66.7%, specificity 95.5%, positive and negative predictive values 96.6% and 56.7%, respectively), with a 14.6 positive likelihood ratio for a cut-off value of 2.32 nmol/L. CONCLUSION: In patients with acute abdominal pain, hospitalized within 24 h of symptom onset, CAPAP in serum and urine was a reliable diagnostic marker of acute pancreatitis. Urinary trypsinogen-2 test strip showed a clinical value similar to amylase and lipase. Urinary TAP was not a useful screening test for the diagnosis of acute pancreatitis.     

Magnifying endoscopy for the diagnosis of specialized intestinal metaplasia in short-segment Barrett’s esophagus

AIM:To determine whether magnified observation of short-segment Barrett’s esophagus(BE)is useful for the detection of specialized intestinal metaplasia(SIM).METHODS:Thirty patients with suspected short-segment BE underwent magnifying endoscopy up to×80.The magnified images were analyzed with respect to their pit-patterns,which were simultaneously classified into five epithelial types[Ⅰ(small round),Ⅱ(straight),Ⅲ(long oval),Ⅳ(tubular),Ⅴ(villous)]by Endo’s classification.Then,a 0.5%solution of methylene blue(MB)was sprayed over columnar mucosa.The patterns of the magnified image and MB staining were analyzed.Biopsies were obtained from the regions previously observed by magnifying endoscopy and MB chromoendoscopy.RESULTS:Three of five patients with a typeⅤ(villous)epithelial pattern had SIM,whereas 21 patients with a non-typeⅤepithelial patterns did not have SIM.The sensitivity,specificity,accuracy,positive predictive value,and negative predictive value of pit-patterns in detecting SIM were 100%,91.3%,92.3%,60%and100%,respectively(P=0.004).Three of the 12 patients with positive MB staining had SIM,whereas 14patients with negative MB staining did not have SIM.The sensitivity,specificity,accuracy,positive predictive value,and negative predictive value of MB staining in detecting SIM were 100%,60.9%,65.4%,25%and100%,respectively(P=0.085).The specificity and accuracy of pit-pattern evaluation were significantly superior compared with MB staining for detecting SIM by comparison with the exact McNemar’s test(P=0.0391).CONCLUSION:The magnified observation of a shortsegment BE according to the mucosal pattern and its classification can be predictive of SIM.     

Significance of antineutrophil cytoplasmic antibody in adult patients with Henoch-Schnlein purpura presenting mainly with gastrointestinal symptoms

AIM: To test the clinical significance of antineutrophil cytoplasmic antibody (ANCA) in evaluation of adult Henoch-Schnlein purpura (HSP) patients presenting mainly with abdominal symptoms. METHODS: Twenty-eight consecutive HSP patients who presented predominantly with abdominal symptoms were enrolled in this study. Control subjects included 27 age-and sex-matched patients with peptic ulcer disease,colon cancer,acute gastroenteritis,irritable bowel syndrome and colonic polyps. ANCA was measured by indirect immunofluorescence (ⅡF) in all patients,and follow-up ELISA was performed in patients with positive ⅡF tests. RESULTS: ANCA was detected in 9 HSP patients by ⅡF (2 were positive for c-ANCA and 7 were positive for p-ANCA). No ANCA was found in the control group. The sensitivity and specifi city of a positive ANCA test (either c-or p-ANCA) were 32.1% and 100% respectively. Only one out of the 9 patients with positive ANCA by ⅡF had positive ANCA by ELISA and the antigen was myeloperoxidase (MPO). The patients positive for ANCA had higher HSP clinical scores,and were more likely to have renal function impairment. Patients with late purpura development were also associated with more severe clinical manifestations. CONCLUSION: A positive ANCA test is associated with more severe symptoms in HSP. After inflammatory bowel disease is excluded,a positive ANCA test provides a clue to the diagnosis of HSP presenting predominantly with abdominal symptoms.     

Cytokeratins and carcinoembryonic antigen in diagnosis, staging and prognosis of colorectal adenocarcinoma

AIM: To evaluate the serum levels of cytokeratins and carcinoembryonic antigen (CEA) in diagnosis, staging and prognosis of patients with colorectal adenocarcinoma.METHODS: The sample consisted of 169 patients. One hundred blood donors formed the control group. Radical surgery was performed on 120 patients, with an average follow-up duration of 22.3mo. Relapses occurred in 23individuals after an average of 18.09mo. CEA was assayed via the Delfia method with a limit of 5ng/mL. Cytokeratins were assayed via the LIA-mat TPA-M Prolifigen method with a limit of 72U/L. RESULTS: In the diagnosis of patients with colorectal adenocarcinoma, CEA showed a sensitivity of 56%, a specificity of 95%, a positive predictive value of 94%, a negative predictive value of 50% and an accuracy of 76.8%. TPA-M had a sensitivity of 70%, a specificity of 96%, a positive predictive value of 97%, a negative predictive value of 66% and an accuracy of 93.6%. The elevation of one of the markers was shown to have a sensitivity of 76.9%, a specificity of 91%, a positive predictive value of 93.5%, a negative predictive value of 70% and an accuracy of 83.6%. There was no variation in the levels of the markers according to the degree of cell differentiation while there was an elevation in their concentrations in accordance with the increase in neoplastic dissemination. There was a statistically significant difference between the patients with stage Ⅳ lesions and those with stages Ⅰ, Ⅱ and Ⅲ tumors.With regard to CEA, the average level was 14.2ng/mL in patients with stage Ⅰ lesions, 8.5ng/mL in patients with stage Ⅱ lesions, 8.0ng/mL in patients with stage Ⅲ lesions and 87.7ng/mL in patients with stage Ⅳ lesions. In relation to TPA-M, the levels were 153.1U/L in patients with stage Ⅰ tumors, 106.5U/L in patients with stage Ⅱ tumors, 136.3U/L in patients with stage Ⅲ tumors and 464.3U/L in patients with stage Ⅳ tumors. There was a statistical difference in patients with a high CEA level in relation to a shorter survival (P&lt;0.05). However, there was no correlation between patients with high TPA-M levels and prognostic indices of patients undergoing radical surgery.CONCLUSION: Cytokeratins demonstrate a greater sensitivity than CEA in the diagnosis of colorectal adenocarcinoma. There is an increase in the sensitivity of the markers with tumor dissemination.Cytokeratins cannot identify the worse prognosis in patients undergoing radical surgery.Cytokeratins constitute an advance in the direction of a perfect tumor marker in the treatment of patients with colorectal cancer.     

Cytokeratms and carcinoembryonic antigen in diagnosis, staging and prognosis of colorectal adenocarcinoma

AIM: To evaluate the serum levels of cytokeratins and carcinoembryonic antigen (CEA) in diagnosis, staging and prognosis of patients with colorectal adenocarcinoma. METHODS: The sample consisted of 169 patients. One hundred blood donors formed the control group. Radical surgery was performed on 120 patients, with an average follow-up duration of 22.3 mo. Relapses occurred in 23 individuals after an average of 18.09 mo. CEA was assayed via the Delfia method with a limit of 5 ng/mL Cytokeratins were assayed via the LIA-mat TPA-M Prolifigen method with a limit of 72 U/L. RESULTS: In the diagnosis of patients with colorectal adenocarcinoma, CEA showed a sensitivity of 56%, a specificity of 95%, a positive predictive value of 94%, a negative predictive value of 50% and an accuracy of 76.8%. TPA-M had a sensitivity of 70%, a specificity of 96%, a positive predictive value of 97%, a negative predictive value of 66% and an accuracy of 93.6%. The elevation of one of the markers was shown to have a sensitivity of 76.9%, a specificity of 91%, a positive predictive value of 93.5%, a negative predictive value of 70% and an accuracy of 83.6%. There was no variation in the levels of the markers according to the degree of cell differentiation while there was an elevation in their concentrations in accordance with the increase in neoplastic dissemination. There was a statistically significant difference between the patients with stage IV lesions and those with stages I, II and III tumors. With regard to CEA, the average level was 14.2 ng/mL in patients with stage I lesions, 8.5 ng/mL in patients with stage II lesions, 8.0 ng/mL in patients with stage III lesions and 87.7 ng/mL in patients with stage IV lesions. In relation to TPA-M, the levels were 153.1 U/L in patients with stage I tumors, 106.5 U/L in patients with stage II tumors, 136.3 U/L in patients with stage III tumors and 464.3 U/L in patients with stage IV tumors. There was a statistical difference in patients with a high CEA level in relation to a shorter survival (P<0.05). However, there was no correlation between patients with high TPA-M levels and prognostic indices of patients undergoing radical surgery. CONCLUSION: Cytokeratins demonstrate a greater sensitivity than CEA in the diagnosis of colorectal adenocarcinoma. There is an increase in the sensitivity of the markers with tumor dissemination. Cytokeratins cannot identify the worse prognosis in patients undergoing radical surgery, Cytokeratins constitute an advance in the direction of a perfect tumor marker in the treatment of patients with colorectal cancer.     

Carbohydrate malabsorption in patients with non-specific abdominal complaints

Non-specific abdominal complaints are a considerable problem worldwide. Many patients are affected and many differential diagnoses have to be considered. Among these, carbohydrate malabsorption seems to play an important role. However, so far, only incomplete absorption of lactose is broadly accepted, while the malabsorption of fructose and sorbitol is still underestimated, although in many parts of the world it is much more frequent. Despite the success of dietary interventions in many patients, there are still a lot of unanswered questions that make further investigations     

A very high frequency index of heart rate variability for evaluation of left ventricular systolic function and prognosis in chronic heart failure patients using five-minute electrocardiogram

Objective A novel index based on fi-equency-domain analysis of heart rate variability （HRV） was tested on patients with reduced left ventricular systolic function. This index, namely VHFI, was defined as the very high frequency （VHF） component of the power spectrum normalized to represent its relative value in proportion to the total power minus the very low frequency component. Methods Patients （n = 130） were divided into a study group, consisting 66 patients with decreased left ventricular systolic function, and a control group, consisting 64 patients with normal heart structure and function and without severe coronary artery stenosis （〈 50%）. Results VHFI in the study group was significantly higher than that in the control group （19.17 ± 13.35 vs 11.37 ± 10.77, P 〈 0.001）. Cardiac events occurred in 18 patients during follow-up （33.34 i 3.26 months）. Defining the positive test as VHFI =15 and negative test as VHFI 〈15, achieved a sensitivity of 57.58% and a specificity of78.13% for predicting decreased left ventricular systolic function, and achieved a sensitivity of 66.67% and a specificity of 64.29% for predicting cardiac events. Univariate Cox regression analysis showed that positive VHFI test was an independent variable in predictive cardiac events. Conclusions The results suggest that VHFI is a useful tool for quick evaluation of left ventricular systolic function and prediction of prognosis     

Breath tests and irritable bowel syndrome

Breath tests are non-invasive tests and can detect H2and CH4 gases which are produced by bacterial fermentation of unabsorbed intestinal carbohydrate and are excreted in the breath.These tests are used in the diagnosis of carbohydrate malabsorption,small intestinal bacterial overgrowth,and for measuring the orocecal transit time.Malabsorption of carbohydrates is a key trigger of irritable bowel syndrome(IBS)-type symptoms such as diarrhea and/or constipation,bloating,excess flatulence,headaches and lack of energy.Abdominal bloating is a common nonspecific symptom which can negatively impact quality of life.It may reflect dietary imbalance,such as excess fiber intake,or may be a manifestation of IBS.However,bloating may also represent small intestinal bacterial overgrowth.Patients with persistent symptoms of abdominal bloating and distension despite dietary interventions should be referred for H2 breath testing to determine the presence or absence of bacterial overgrowth.If bacterial overgrowth is identified,patients are typically treated with antibiotics.Evaluation of IBS generally includes testing of other disorders that cause similar symptoms.Carbohydrate malabsorption(lactose,fructose,sorbitol)can cause abdominal fullness,bloating,nausea,abdominal pain,flatulence,and diarrhea,which are similar to the symptoms of IBS.However,it is unclear if these digestive disorders contribute to or cause the symptoms of IBS.Research studies show that a proper diagnosis and effective dietary intervention significantly reduces the severity and frequency of gastrointestinal symptoms in IBS.Thus,diagnosis of malabsorption of these carbohydrates in IBS using a breath test is very important to guide the clinician in the proper treatment of IBS patients.     

Prevalence of celiac disease in Iranian children with idiopathic short stature

AIM： To determine the prevalence of celiac disease （CD） in children with idiopathic short stature （ISS） and the diagnostic value of immunoglobulin （Ig） A G antigliadin antibodies （AGA） and transglutaminase （TTG） antibodies for CD.METHODS： A total of 104 children （49 male, 55 female） with ISS without a specific etiology were studied. Extensive endocrine investigations had shown no abnormalities in any subject. Anthropometric parameters and IgA AGA and IgA TTG antibodies were evaluated in this study group. These antibodies were measured by enzyme-linked immunosorbent assay. All patients were referred for an endoscopic intestinal biopsy. The biopsy samples were classified according to revised Marsh criteria （UEGW 2001）.RESULTS： We detected positive IgA TTG antibodies in 36 and IgA AGA in 35 of these patients. Thirty one IgA TTG antibody positive and 28 IgA AGA positive subjects showed histological abnormalities compatible with celiac disease （33.6%）. Sensitivity, specificity, positive predictive value （PPV） and negative predictive value for IgA AGA were found to be 80%, 88.4%, 77.8% and 89.7%, respectively. Sensitivity, specificity and PPV for IgA TTG antibodies were 88.6%, 94.2% and 88.6%, espectively.CONCLUSION： We conclude that the prevalence of celiac disease is high in patients with ISS and it is important to test all children with ISS for celiac disease by measuring serologic markers and performing an intestinal biopsy.