Irritable bowel syndrome and bronchial hyperresponsiveness: is there a link?

Review article: Physical and psychological comorbidities associated with irritable bowel syndrome

Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders encountered by physicians in primary and secondary care. Patients with IBS commonly present with various extraintestinal complaints, which account for a substantial clinical and economic burden. The common extraintestinal comorbidities associated with IBS include anxiety, depression, somatisation, fibromyalgia, chronic fatigue syndrome, chronic pelvic pain, interstitial cystitis, sexual dysfunction and sleep disturbance. The presence of comorbidity in IBS poses a diagnostic and therapeutic challenge with patients frequently undergoing unnecessary investigations and interventions, including surgery. This review discusses the different physical and psychological comorbidities associated with IBS, the shared pathophysiological mechanisms and potential management strategies.

Prevalence and Symptom Characteristics of Irritable Bowel Syndrome Among Bronchial Asthma Patients in Pakistan

INTRODUCTION

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder that leads to a variety of symptoms including abdominal discomfort and change in stool frequency and consistency. Asthma is a common disease of the airway. Some studies have suggested that a relationship between IBS and asthma exist, while others have contradicted the claim. This study aims to determine the prevalence of IBS in asthmatic patients and compare their symptoms with symptoms of IBS patients in non-asthmatic patients.

METHODOLOGY

In this case-control study, 100 known and documented asthmatic patients were included as cases, and 100 non-asthmatic healthy patients were included as controls from July to August 2019. These patients were given a questionnaire based on ROME II criteria for the diagnosis of IBS. Prevalence and symptoms of IBS were compared between cases and controls. A probability level, P < 0.05 was considered significant.  Result: IBS was found in 41 out of 100 asthma patients (41%) and 18 out of 100 controls (18%) with a P-value of 0.0005 and was more common in females in both asthmatic (63.41%) and non-asthmatic patients (66.66%). Symptoms such as abdominal pain/distress (63.41% vs. 11.11%, P-value: 0.0013) and bloating (82.92% vs. 33.33%, P-value: 0.0005) were significantly higher in asthmatic patient with IBS compared to non-asthmatic patient with IBS.

CONCLUSION

Prevalence of IBS among asthma patients was significantly higher as compared to non-asthmatics. Routine screening of asthma patients and further studies to understand the pathogenesis underlying association between IBS and asthma should be conducted to detect and manage such patients effectively.

Association between irritable bowel syndrome and asthma: a meta-analysis and systematic review

Background:

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder often seen in outpatient clinics. Diagnosing IBS is often challenging, as it frequently presents with other complicated rheumatological and psychiatric conditions. Asthma has often been associated with gastrointestinal conditions such as gastroesophageal reflux disease and eosinophilic esophagitis. This review and meta-analysis aimed at a better understanding of the association between the conditions.

Methods:

A comprehensive literature review was completed using MEDLINE and EMBASE databases through January 2019. Case-control, cross-sectional and cohort studies that evaluated the association between asthma and IBS were divided into 2 groups: the first included studies that identified patients with asthma first and then looked for the presence of IBS. The second group included studies that identified IBS patients first and then looked for the presence of asthma. Random effects meta-analysis was conducted using STATA 15.

Results:

The search strategy generated a total of 634 studies and 10 eligible studies (8 case-control and 2 cross-sectional) were selected for meta-analysis. Analysis showed that asthmatics have twice the risk of having IBS (pooled odds ratio [OR] 2.0, 95% confidence interval [CI] 1.5-2.8), and patients with IBS have twice the risk of having asthma (pooled OR 2.2, 95%CI 1.3-3.9).

Conclusions:

This study highlights that the risk of asthma is considerably higher in IBS patients and vice versa. Physicians should look out for pulmonary symptoms in IBS patients and consider evaluation with spirometry when necessary. Likewise, asthmatics presenting with gastrointestinal symptoms may need consultation and evaluation for IBS.

Irritable Bowel Syndrome and Bronchial Asthma: Are They Associated in Indian Population?

INTRODUCTION

Irritable Bowel Syndrome (IBS), a common gastrointestinal (GI) disorder has been linked with asthma implying a clue to its pathophysiology as being some form of allergic response. Previous studies from other parts of the world have shown both the presence as well as an absence of an association between them.

AIM

We conducted a cross-sectional study to find an association between IBS and asthma, in an Indian cohort.

MATERIALS AND METHODS

Seventy patients of IBS diagnosed by exclusion and ROME III criteria with a matched control group were questioned for GI, respiratory symptoms along with their spirometry analysis. Those having reversible bronchoconstriction were categorized as asthmatic.

RESULTS

The prevalence of asthma in the IBS group of 16 females and 54 males was 12 (17.14%) as compared to 14 (20%) in control group. Chi-square test revealed the Odds Ratio (OR) for prevalence of asthma in IBS as 0.828 with 95% Confidence Interval (CI) between 0.320 and 2.121 (p=0.664) which was non-significant (p>0.05).

CONCLUSION

This study denies the presence of association between IBS and asthma among Indian cohorts and suggests that regional variations are present in the above association.

Association and symptom characteristics of irritable bowel syndrome among bronchial asthma patients in Kuwait

CONTEXT:

Excess prevalence of irritable bowel syndrome in asthma has been reported, suggesting a link between these two conditions.

AIMS:

To investigate the association between irritable bowel syndrome (IBS) and asthma, and explore the symptoms of IBS among asthma patients in Kuwait.

SETTINGS AND DESIGN:

Case control study.

METHODS:

In a tertiary center, for allergy and asthma, 138 patients aged 20-65 years, with asthma, diagnosed clinically and by spirometry, were compared with 145 healthy, non-asthmatic controls matched for age, gender and nationality. Cases and controls completed a self-administered questionnaire of irritable bowel syndrome diagnosis (ROME II criteria).

STATISTICAL ANALYSIS USED:

The data were analyzed using SPSS software, and proportions were tested with Chi-square or Fisher's test. Odds ratio (OR) with 95% Confidence Interval (CI) were calculated to identify the associated risk factors. The demographic variables were selected for logistic regression analysis.

RESULTS:

A significantly large proportion (39.13%) of asthmatics had IBS as compared to 7.93% controls (P < 0.001). A higher proportion of females with IBS were observed in cases and controls (74%, 61.54%). IBS was seen in 87% cases using inhalers, and in 13% with additional oral theophylline (P < 0.001). As many as 66.6% cases, had IBS with relatively short duration of asthma (1-5 years, P < 000). Predominant symptoms of IBS in asthmatics were abdominal discomfort or distension (64.8% vs. 11.5%), (P < 0.000, OR = 14.1; 95%CI: 3.748-53.209), bloated feeling of abdomen (74.1% vs. 34.62% (P < 0.001, OR = 5.38; 95%CI:1.96-14.84)), increased frequency of stools (63%, P < 0.006).

CONCLUSIONS:

Irritable bowel syndrome in asthmatics was significantly high, more in the female asthmatics. Abdominal discomfort, persistent bloated feeling, increased frequency of passing stools were the most common IBS symptoms observed.

Characterization of irritable bowel syndrome and constipation in children with allergic diseases

Allergy is believed to play a role in the pathogenesis of irritable bowel syndrome (IBS) and constipation. We investigated whether allergic patients are more prone to constipation or IBS. In a multicenter study, two groups of outpatient children aged 3-13 years were included. In group 1, children with allergic symptoms were enrolled. Group 2 consisted of nonallergic children. In both groups, the assessment of IBS and constipation was carried out using a questionnaire based on the Rome criteria for functional gastrointestinal disorders. All children were examined and underwent skin prick tests (SPT) to foods and aeroallergens. The allergic group (n=196) and controls (n=127) were comparable with respect to sex, age, and anthropometric parameters. IBS was found in 6.6% of the allergic children and in 6.3% of the controls (p=0.581). The frequency of constipation was similar in the two groups. In allergic children, positive SPTs to food and self-reported reactions to food were associated with IBS. Our results show that evaluation of constipation comorbidity is not required in allergic children. In allergic children with positive SPT to foods attention may be paid to IBS symptoms.

Inhalation of a pulmonary irritant modulates activity of lumbosacral spinal neurons receiving colonic input in rats

The purpose of the present study was to determine whether an intraspinal nociceptive pathway from the lungs modulated activity of spinal neurons that also received afferent input from the colon. Extracellular potentials of single lumbosacral (L6-S2) spinal neurons were recorded in pentobarbital-anesthetized, paralyzed, and ventilated male rats. The lower airways and lungs were irritated by injecting ammonia vapor over a 30% NH(4)OH solution into the inspiratory line of the ventilator (0.5 ml, 20 s). Graded colorectal distension (CRD; 20-60 mmHg, 20 s) was produced by air inflation of a balloon. Inhaled ammonia (IA) altered activity of 31/51 (61%) lumbosacral spinal neurons responding to noxious CRD (60 mmHg, 20 s). In contrast, IA changed activity of 3/30 (10%) spinal neurons with somatic fields that did not respond to colorectal inputs. IA decreased activity of 16/31 (52%) spinal neurons and increased activity of the other 15 neurons with colorectal input. Multiple patterns of viscerovisceral convergent spinal neurons with excitatory and inhibitory responses to CRD and IA were observed; 87% (27/31) of the viscerovisceral convergent neurons also responded to innocuous and/or noxious stimuli of somatic fields. Bilateral cervical vagotomy abolished responses to IA in 2/8 tested neurons, indicating that the remaining 6 neurons had input originating from sympathetic afferent fibers. Rostral C1 spinal transection did not abolish inhibitory responses to IA in 4/4 neurons, but L2 transection eliminated inhibitory responses to IA in 3/3 neurons. These results indicated that irritation of the lower airways modulated activity of lumbosacral spinal neurons with colorectal input. It might contribute to intraspinal cross talk between the colon and lungs.

Incidence of IBS in a cohort of people with asthma

We conducted a study to examine the relation of asthma and its treatment to irritable bowel syndrome (IBS). We identified cohorts of members with and without asthma from January 1996 though June 2002 and calculated rates of IBS in both cohorts. In a nested case-control study, we calculated odds ratios for oral steroid dispensing before IBS onset. To address differential IBS detection, we conducted a quantitative sensitivity analysis. We identified 91,237 people with asthma and sample of 24,518 people without asthma. There was a 20% increase in the incidence of IBS among people with asthma (standardized morbidity ratio = 1.2; 95% CI, 1.0-1.5), and no association between oral steroids and IBS among people with asthma (OR = 1.0; 95% CI, 0.9-1.1.) Misclassification of IBS would have biased the rate ratio toward the null. We observed a small increase in IBS among people with asthma, and no association between oral steroids and IBS onset among asthma patients.

Physical and psychological co-morbidity in irritable bowel syndrome: a matched cohort study using the General Practice Research Database

BACKGROUND

Irritable bowel syndrome is a common problem known to have a complex relationship with psychological disorders and other physical symptoms. Little information, however, is available concerning physical and psychological comorbidity in irritable bowel syndrome patients studied over an extended period.

AIM

To evaluate physical and psychological morbidity 2 years before and during 6 years after the time of diagnosis in incident cases of irritable bowel syndrome and control subjects.

METHODS

A matched cohort study was implemented in 123 general practices using the General Practice Research Database. Irritable bowel syndrome cases (n = 1827) and controls (n = 3654) were compared for 2 years before and 6 years after diagnosis.

RESULTS

The age-standardized incidence of irritable bowel syndrome in patients over 15 years of age was 1.9 per 1,000 in men and 5.8 per 1,000 in women. From 2 years before the date of diagnosis, more irritable bowel syndrome cases (13%) than controls (5%) consulted with depression or were prescribed antidepressant drugs. Consultation and prescription rates for anxiety were also higher before diagnosis, and both anxiety and depression remained prevalent up to 6 years after diagnosis. Asthma, symptoms of urinary tract infection, gall-bladder surgery, hysterectomy and diverticular disease were recorded more frequently in irritable bowel syndrome patients, who were also more likely than controls to be referred to hospital.

CONCLUSIONS

People who are diagnosed with irritable bowel syndrome experience more anxiety and depression and a range of physical problems, compared with controls; they are more likely to be referred to hospital.

Bronchial hyperresponsiveness in irritable bowel syndrome

Extraintestinal symptoms are often found in patients with irritable bowel syndrome (IBS). Recent studies suggest that IBS is associated with bronchial hyperresponsiveness. But it is still arguable that the bronchial hyperresponsiveness is associated with IBS patients. The purpose of this study is to investigate the possible relationship between IBS and bronchial hyperresponsiveness. Forty-two patients with IBS and 42 control subjects were included in this study. All patients underwent pulmonary function, methacholine challenge, and skin prick tests. There was no statistical difference between the two groups with respect to percentage of all pulmonary function test parameters, including FEV(1)%, FCV%, FVC/FEV(1), and FEF(25 - 75)%. Only two persons in the alternating-type IBS patient group and one person in the control group tested positive in the methacholine provocation test. But all PC(20) values were above 16 mg/ml. These results do not demonstrate a relationship between bronchial hyperresponsiveness and IBS. However, a relationship might exist in a subpopulation of IBS patients.

Interrelationship between Asthma and Functional Bowel Disease

Gastrointestinal abnormalities have been reported in subjects with bronchial asthma. The aim of this study was to evaluate the presence of irritable bowel syndrome (IBS) in subjects with bronchial asthma. 380 asthmatic patients were selected for body mass index (BMI), sex, and age, before undergoing both methacholine challenge test (MCHt) and skin prick tests. 195 asthmatic patients (51.3%) were positive to MCHt, while 185 (41.6 %) were negative. We also found that 17 (8.7%) of the 276 patients with positive MCHt, and 22 (11.8%) of the 185 patients with negative MCHt were affected by IBS. Therefore, there was no statistical significance between positive MCHt tests and IBS. The results do not demonstrate an interrelationship between asthma and IBS.