Comparisons of the Rome III and Rome IV criteria for diagnosis of irritable bowel syndrome in Indian and Bangladeshi communities and internal shifts in the diagnostic categories of bowel disorders of gut-brain interactions

BACKGROUND

Although the Rome IV criteria are the most recent criteria to diagnose irritable bowel syndrome (IBS), their sensitivity has been shown to be low in Chinese and Western populations. There are scanty data comparing the Rome III and Rome IV criteria in diagnosis of IBS in the Indian and Bangladeshi populations where abdominal pain, an essential component of diagnosis of IBS by the Rome IV criteria, is less in frequency and of lower severity.

METHODS

We analyzed the Indian and Bangladeshi data from the Rome Global Epidemiology Study to compare diagnostic sensitivity of the Rome III and Rome IV criteria for IBS, internal shifts in diagnostic categories of disorders of gut-brain interaction (DGBI), the severity of IBS diagnosed by the Rome III and Rome IV criteria, and consultation patterns in these populations.

KEY RESULTS

The Rome IV criteria were less sensitive than the Rome III criteria to diagnose IBS in these populations, and the subjects with Rome III IBS shifted internally to other DGBI when the Rome IV criteria were applied. Moreover, Rome IV IBS subjects had greater symptom severity than the Rome III IBS. A third of people fulfilling diagnostic criteria for IBS consulted doctors, and those diagnosed using Rome IV criteria, those with higher anxiety and depression symptom score, lower global physical health score, and greater IBS symptom severity score had greater correlation coefficients with doctors' consultation.

CONCLUSIONS AND INFERENCES

The Rome IV diagnostic criteria for IBS are less sensitive than the Rome III criteria in Indian and Bangladesh communities. Application of the Rome IV criteria to people who meet the Rome III IBS criteria selects a subgroup of people with greater severity of symptoms, and hence, Rome IV IBS is more strongly associated with physician consultation. These findings may have important bearing in future iterations of the Rome criteria for a broader global applicability.

The low-FODMAP diet and the gluten-free diet in the management of functional abdominal bloating and distension

This review summarizes current knowledge on the role of low-FODMAP diet and gluten-free diet in functional abdominal bloating and distension, an emerging disorder of gut-brain interaction characterized by remarkable costs for healthcare systems and a significant impact on the patient's quality of life. Ingested food plays a key role in the pathophysiology of disorders of gut-brain interaction as up to 84% of patients with irritable bowel syndrome (IBS) report food-triggered symptoms. Potential pathogenetic mechanisms of food-related symptoms in these patients are discussed, focusing on bloating and abdominal distension. These mechanisms provide the rationale for dietary treatment in patients with functional abdominal bloating and distension. The role of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) and gluten in functional abdominal bloating and distension is examined. Current literature evaluating the efficacy of the low-FODMAP diet and the gluten-free diet in abdominal bloating and distension is analyzed. Available evidence originates mainly from studies on patients with IBS, since clinical studies on selected cohorts of patients with only functional abdominal bloating and distension have been missing to date. Promising evidence on the potential efficacy of the low-FODMAP diet in functional abdominal bloating and distension is provided by the reduction of the bloating observed in patients with IBS. Regarding the gluten-free diet, there is insufficient evidence to recommend it to reduce bloating and abdominal distension. In conclusion, this review asserts the need for a close collaboration with experts in nutrition to optimize the management of these patients and reduce the risks associated with elimination diets.

Mast cell-nerve interactions correlate with bloating and abdominal pain severity in patients with non-celiac gluten / wheat sensitivity

BACKGROUND

Gastrointestinal (GI) and extra-GI symptoms/manifestations represent key clinical features of patients with non-celiac gluten/wheat sensitivity (NCG/WS). This study aimed to investigate neuro-immune (focusing on mast cells, MCs) interactions in the duodenal submucosa of patients with NCG/WS.

METHODS

Submucosal whole mounts from duodenal biopsies of 34 patients with self-reported NCG/WS, 28 with celiac disease (CD), 13 with functional dyspepsia (FD), and 24 healthy controls (HC) were analyzed by immunohistochemistry. Quantitative data on neuronal and MCs density and the percentage of MCs in close vicinity to nerves were obtained, and correlations among neurons, MC density and MC-nerve distance (D), and symptoms were assessed in the three groups.

KEY RESULTS

The number of submucosal neurons was not different among groups. In NCG/WS, MC density was not different from HC, while it was slightly increased vs. CD (P = .07) and significantly decreased vs. FD (P < .05). The percentage of MCs close to nerves (D < 15 µm) was similarly increased in all three pathological groups vs. HC (P < .001). In NCG/WS, MC infiltration correlated with bloating (P = .001) and abdominal pain severity (P = .03) and the percentage of MCs in proximity to neurons correlated with the number of GI symptoms (D < 5 µm; P = .05), bloating and abdominal pain severity (D < 15um; P = .01).

CONCLUSIONS AND INFERENCES

Submucosal MC infiltration and the close (within 15 µm) MC-to-nerve proximity in the duodenum of NCG/WS patients are features providing a histopathological basis to better understand GI symptoms in this condition.

Efficacy and safety of APT036 versus simethicone in the treatment of functional bloating: a multicentre, randomised, double-blind, parallel group, clinical study

Background

Bloating is a common symptom reported by around 16% to 31% of the general population. Functional bloating is diagnosed in patients with recurrent symptoms of bloating who do not meet the diagnostic criteria of irritable bowel syndrome or other functional gastrointestinal disorders.

Methods

This double-blind, multicentre, randomised study compared the safety and efficacy of APT036 (xyloglucan plus tyndallized Lactobacillus reuteri and Bifidobacterium brevis; Aprotecol^®) and simethicone in treating functional bloating in adults. APT036 or simethicone were administered orally (3 times/day) for 20 consecutive days, with evaluations at baseline, and on Days 2, 10, 20 (end of treatment) and 30 (follow-up visit). The main outcome measure was safety. Efficacy was assessed at each visit by patient-reported symptom severity (Likert scale) and abdominal girth measurement. A hydrogen breath test was performed at baseline and Day 20.

Results

Both APT036 (n=54) and simethicone (n=54) were well tolerated by study subjects; no adverse effects were reported with either treatment. Compared with simethicone, APT036 significantly reduced abdominal distension (P=0.008) and flatulence (P=0.010) from baseline to Day 30. The baseline hydrogen breath test confirmed the presence of small intestinal bacterial overgrowth (SIBO) in all subjects. At Day 20, mean hydrogen gas elevation was below the threshold for a diagnosis of SIBO (<12 ppm above basal on glucose administration) in both study arms.

Conclusions

Both APT036 and simethicone had good safety profiles but APT036 was superior to simethicone in relieving symptoms of functional bloating.

Impaired reflex control of intestinal gas transit in patients with abdominal bloating

BACKGROUND

Patients with abdominal bloating and distension exhibit impaired transit of intestinal gas which may lead to excessive gas retention and symptoms. Furthermore, we have previously shown that intestinal gas transit is normally accelerated by rectal distension. We hypothesise that in patients with functional bloating this modulatory mechanism fails and impairs gas transit.

METHODS

In 12 healthy subjects and eight patients with abdominal bloating we compared, by paired studies, the effect of rectal versus sham distension on intestinal gas transit. Gas was infused into the jejunum (12 ml/min) for three hours with simultaneous perfusion of lipids into the duodenum (Intralipid 1 kcal/min) while measuring evacuation of gas per rectum.

RESULTS

In healthy subjects, duodenal lipid infusion produced gas retention (409 (68) ml) which was prevented by rectal distension (90 (90) ml; p<0.05 v sham distension). In contrast, rectal distension in patients with abdominal bloating failed to reduce lipid induced gas retention (771 (217) ml retention during rectal distension v 730 (183) ml during sham distension; NS; p<0.05 v healthy controls for both).

CONCLUSION

Failure of distension related reflexes impairs intestinal gas propulsion and clearance in patients with abdominal bloating.

Intestinal gas distribution determines abdominal symptoms

BACKGROUND

Patients with functional gut disorders manifest poor tolerance to intestinal gas loads but the mechanism of this dysfunction is unknown.

AIM

Our aims were firstly, to explore the relative importance of the amount of intestinal gas versus its distribution on symptom production, and secondly, to correlate gut motility and perception of gas loads.

SUBJECTS

Fourteen healthy subjects with no gastrointestinal symptoms.

METHODS

In each subject a gas mixture was infused (12 ml/min) either into the jejunum or rectum for one hour during blocked rectal gas outflow, and subsequently gas clearance was measured over one hour of free rectal evacuation. We measured abdominal perception, distension, and gut tone by duodenal and rectal barostats.

RESULTS

Similar magnitude of gas retention (720 ml) produced significantly more abdominal symptoms with jejunal compared with rectal infusion (perception score 4.4 (0.4) v 1.5 (0.5), respectively; p<0.01) whereas abdominal distension was similar (15 (2) mm and 14 (1) mm girth increment, respectively). Jejunal gas loads were associated with proximal contraction (by 57 (5)%) and colonic loads with distal relaxation (by 99 (20)%).

CONCLUSION

The volume of gas within the gut determines abdominal distension whereas symptom perception depends on intraluminal gas distribution and possibly also on the gut motor response to gas loads.