Irritable bowel syndrome in students at the University of Abomey-Calavi (Benin): epidemiological, clinical and therapeutic aspects

¹University Hepato-gastroenterology Clinic, National Center Hospitalier and University Hubert Koutoukou Maga, Cotonou, Benin, ²Faculty of Health Sciences, University of Abomey-Calavi, Cotonou, Benin, ³Hepato-gastroenterology Department, Mohammed VI University Hospital, Marrakech, Morocco, ⁴Department of Internal Medicine, National Hospital Donka, Conakry, Guinea

^&Corresponding author
Aboudou Raïmi Kpossou, University Hepato-gastroenterology Clinic, National Center Hospitalier and University Hubert Koutoukou Maga, Cotonou, Benin

Introduction    

Functional bowel disorders (FBD) are a range of chronic Gastrointestinal (GI) disorders characterized by symptoms or predominant signs of abdominal pain, bloating, distension and/or abnormal bowel transit (constipation, diarrhea or alternating constipation) [1]. They can be distinguished from other gastrointestinal disorders on the basis of chronicity (6 months of symptoms at presentation), current activity (symptoms present within the last 3 months), frequency (symptoms present, on average, at least 1 day per week) and the absence of obvious anatomical or physiological abnormality identified by routine diagnostic tests, deemed clinically appropriate [1]. Irritable bowel syndrome (IBS) is one form of Interferential therapy (IFT) in which recurrent abdominal pain is associated with defecation or a change in bowel habits [1,2]. Symptoms must have appeared at least 6 months prior to diagnosis and have been present for the last 3 months [1-3]. It is the most frequent functional disorder, with a worldwide prevalence estimated at 11%, but varying according to geographical region [2], generating a large number of consultations [4]. In France, prevalence is estimated at 4-5% [2]. In Asia, prevalence varies from 2.9% to 15.6% [5]. In the United States, it is 14.1% [6]. In Africa, very few studies have looked at IBS in certain socioprofessional groups with different Rome criteria. In Nigeria, for example, a study on a population of students reported a prevalence of 26.1% according to the Rome II criteria [7], whereas it was 27.5% among medical students in Egypt according to the Rome III criteria [8]. However, in Benin, Sehonou et al. [9] found a prevalence of 14% among medical students according to Rome IV criteria. A female predominance was noted in most studies [1,2,7,9,10] except in India and Côte d'Ivoire, where a male predominance was reported [7,11].

Its pathophysiology is complex and multifactorial, with peripheral factors (digestive motor disorders, intestinal micro-inflammation, disorders of intestinal permeability, role of microbiota) and central factors (visceral hypersensitivity, abnormalities in medullary and cortical pain control, psychological factors) and a role for diet [1,3]. IBS results in an altered quality of life that correlates with symptom intensity [12]. Its management is complex, involving several medical and alternative therapies aimed at controlling symptoms [2-4]. As the frequency of IBS was found to be high among medical students [9], it was timely to conduct a larger-scale study to better understand the factors involved. The aim of this study was to describe the epidemiological, clinical and therapeutic aspects of IBS in students at the University of Abomey-Calavi in Benin.

Methods     

Study design and setting

The study has taken place on the campuses of the University of Abomey-Calavi (UAC). It was a descriptive and analytical cross-sectional study that had covered a period of three and a half months from March 03 to June 20, 2018.

Study population

The study population consisted of students at the University of Abomey-Calavi (UAC).

Inclusion criteria: subjects meeting the following conditions were included in the study: 1) be enrolled at the University of Abomey-Calavi during the current academic year; 2) have given informed consent.

Exclusion criteria: non-inclusion criteria. Students were not included in this study: 1) with a personal history of organic intestinal pathology (chronic inflammatory bowel disease - Crohn's disease or ulcerative colitis; colorectal cancer); 2) presenting alarm signs: rectorrhagia, melaena, anaemia, significant and unexplained weight loss; 3) pregnant animals.

Sampling

Sample size: the minimum population size was determined by Schwartz's formula, n= (i² x p x q)/α².

With n = sample size; i= smallest deviation at 95% confidence level (i= 1.96); p= prevalence estimated from a previous survey; q= 1-p (q= 85%); α= precision 4% (α= 0.04); n= (1.962 X 0.25X 0.75) / 0.042 and n = 450.18. We added 10% to the number obtained, taking into account response errors and non-responses, to obtain the final number.

N= n+ (n x 10%) i.e. N= 450.18 + (450.18 x 0.1) = 495.20

To better represent the number of students, we have reduced the sample to 500 students.

Sampling method and technique: initially, we carried out purposive sampling to select university centers hosting UAC training units. Then, in view of our objectives, we immediately chose the Faculty of Health Sciences (FHS) and the "medicine" stream. Finally, to select the other streams, we used three-stage random sampling. This involved progressive sampling at 3 levels: the training institution, the stream and the selection of students to be surveyed by year of study.

For the choice of university center: UAC's training entities are spread across seven (07) university centers, namely: Cotonou, Abomey-Calavi, Porto-Novo, Lokossa, Aplahoué, Dangbo and Ouidah. For reasons of cost and time, we have selected two major university centers (Abomey-Calavi and Cotonou) out of these seven, home to the largest number of students.

For the choice of entity, we carried out a simple random survey at this level, followed by a choice of two entities in each university center. We placed two ballot boxes bearing the name of each of the pre-selected centers. We drew lots without discount within the pre-selected university centers, and selected the following entities: the National School of Applied Economics and Management (NSAEM) in addition to the Faculty of Health Sciences (FHS) for Cotonou and the Faculty of Science and Technology (FAST) and the Faculty of Letters, Languages, Arts and Communications (FLLAC) for Abomey-Calavi.

For the choice of stream, we applied the previous principle of drawing lots without discount in each entity, resulting in the selection of the following streams: statistics for NSAEM, Mathematics and Applied Informatics (MAI) for FAST and German for FLLAC. For the selection of respondents, we used a simple random sample. Using the table of student numbers by stream and year, we determined the number of respondents to be selected by year.

Data collection

Data were collected on a standard questionnaire designed for this purpose during a face-to-face interview.

Definitions

The dependent variable was IBS, defined on the basis of the Rome IV diagnostic criteria [13]. Based on the definition of IBS and stool characteristics, subgroups were also defined according to the predominance of diarrhea or constipation associated with IBS. The different forms of IBS were identified using the Bristol Stool Consistency Scale [13], ranging from hard, fragmented (marble-like) stools with difficult evacuation (type 1), hard, sausage-like and lumpy stools (type 2), hard, with a cracked surface (type 3), soft but sausage-moulded stools (type 4), soft broken stools with clean edges and easy evacuation (type 5), soft broken stools with ragged edges (type 6) and totally liquid stools (type 7).

The independent variables were sociodemographic data, clinical data relating to IBS, therapeutic data, disturbance of quality of life, lifestyle, dietary habits, data relating to psychological disturbance such as anxiety and depression, which were assessed using the Hospital Anxiety and Depression Scale (HADS score), HADS score-anxiety for anxiety and HADS score-depression for depression [14]. Stress was assessed using the Perceived stress scale (PSS) [15].

Data entry and statistical analysis

Data were coded and entered into Excel 2007. Data processing and analysis were carried out using SPSS 20.0 and Stata version 15. Quantitative variables were expressed as mean and standard deviation. Qualitative variables were expressed as headcount and percentage. Univariate and multivariate analyses were used to identify factors associated with IBS. For univariate analysis, frequency comparisons were made using Pearson's chi-2 test. For multivariate analysis, a stepwise, top-down logistic regression model with successive iterations was used. The initial model included all variables with a significance level ≤ 0.20 in univariate analysis. The interaction between the factors finally retained as significant had been tested and the adequacy of the final model had been tested by the Hosmer-Lemeshow test. Measures of association were estimated by ajusted Odds Ratio (aOR) and their 95% confidence intervals. A p-value <0.05 was considered statistically significant.

Ethical considerations

To guarantee data confidentiality, the forms were designed to respect participants' anonymity. Verbal informed consent was obtained from the student prior to completion.

Results     

Population characteristics

A total of 536 UAC students were included. The mean age of these students was 21.6±2.4 years, with extremes of 16 and 29 years. Males predominated at 65.1% (n= 349), with a sex ratio of 1.9. The vast majority of students surveyed 95.1% (n= 532) were single; 80.8% (n= 433) of them had no pathological antecedents; 47.4% (n= 254) practiced sport occasionally; 45.9% (n= 246) consumed alcoholic beverages at least once a month. In addition, 86% (n= 461) had a cereal-based diet, 66.4% had a sweet diet. It was observed that 30.4% of students (n= 163) had moderate anxiety and 4.7% (n= 25) severe anxiety. Moderate depression was observed in 19.8% of students (n= 106). The majority of students (90.3%, n= 484) had an average stress level (Table 1, Table 2, Table 3).

Prevalence of IBS and its subtypes, clinical features of IBS and impact on quality of life

The prevalence of IBS in the study population was 11.9% (n= 64). The unspecified subtype was the most frequent, 37.4% (n= 24), with diarrhea or constipation in equal proportions (31.3%). The dominant symptom was abdominal pain in 93.8% (n= 60) of surveyed subjects with IBS, followed by abdominal discomfort with extra-digestive signs such as migraine and asthenia in half the cases. Some students with IBS were also found to have functional dyspepsia (35.9%, n= 23), and gastro-oesophageal reflux disease (31.3%, n= 20). Factors aggravating the symptoms, such as diet, lack of sleep, medication and studies, were identified in 64.1% (n= 41). Some students had labored exoneration 37.5% (n= 24) and unsatisfactory exoneration 45.3% (n= 29). IBS impacted quality of life, leading to absenteeism 35.9% (n= 23) and work stoppage 53.1% (n= 34). In terms of treatment, self-medication was more common, at 59.4% (n= 38), and non-conventional (traditional) treatment was more prevalent, at 43.8% (n= 28) (Table 4, Table 5).

Associated factors

In univariate analysis, there was an association between IBS and gender (p= 0.006), Yorouba ethnicity (p= 0.022), marital status (p= 0.005), personal history of sickle cell disease (p= 0.020), regular consumption of soft drinks (p= 0.040) and anxiety (p= 0.020). In multivariate analysis, IBS was associated with female gender (aOR: 1.09; 95% CI 1.01-1.17, p= 0.006), Yorouba ethnicity (aOR: 3.61; 95% CI 1.20-10.85, p= 0.022), married status (aOR: 0.28; 95% CI 0.11-0.72, p= 0.005), a personal history of sickle cell disease (aOR: 0.25 ; 95% CI 0.07-0.88, p= 0.020), irregular consumption of soft drinks (aOR: 0.57; 95% CI 0.34-0.98, p= 0.040), moderate anxiety (aOR: 2.26; 95% CI 1.13-4.53, p= 0.020) and severe anxiety (aOR: 9.82; 95% CI 3.77-25.58, p= 0.000). There was no association between IBS and age, course of study, year of study or other socio-demographic factors (Table 2, Table 3).

Discussion     

This study aimed to describe the epidemiological, clinical and therapeutic aspects of IBS in students at the University of Abomey-Calavi in Benin. The prevalence of IBS among students based on Rome IV criteria was 11.9%, with the unspecified subgroup being the most frequent. The main clinical manifestation was abdominal pain, most often associated with other digestive disorders. IBS impacted their quality of life, leading to absenteeism and work stoppage. Factors associated with IBS were female gender, Yorouba ethnicity, married status, personal history of sickle cell disease, irregular consumption of soft drinks and moderate to severe anxiety. Self-medication and non-conventional treatment were widely used.

The prevalence of IBS was 11.9% among students at the University of Abomey-Calavi. This prevalence was close to those found by Sehonou et al. [9] and Seger et al. [16], who reported a prevalence of 14% and 14.7% (Rome IV) respectively among medical students at the Faculty of Health Sciences in Cotonou and at a private Malaysian university. It was, however, very different from the prevalence found in a Nigerian university (26.1%), based on Rome II criteria [17], 27.5% among medical students in Egypt according to Rome III criteria [8], 31.8% and 28.3% among medical students in Saudi Arabia and Pakistan respectively according to Rome III criteria [17,18]. Prevalence was low when the study involved all students (medical and non-medical), as shown by this survey of all students at Damascus University in Syria [19] and Lebanon [20]. This finding seems to corroborate our results and may be due to the longer duration of study in medicine and the excessive number of examinations [8]. In addition, observed variations in prevalence may be related to cultural, dietary and ethnic patterns, sample sizes, age ranges and diagnostic criteria used in various studies [8]. The influence of gender plays a major role in the onset of symptoms. Worldwide, prevalence is 2 to 2.5 times higher in women than in men [21]. Female sex hormones play a crucial role in the incidence of the disease, mainly through their inhibitory action on smooth muscle contraction in the intestine, which can reduce intestinal motility [2].

Clinically, the main clinical manifestation was abdominal pain, followed by abdominal discomfort and extradigestive manifestations to varying degrees. This finding was similar to those reported in the literature [17]. These symptoms are associated with other disorders of exonerative changes to varying degrees, making it possible to define the predominant subtype of IBS and sometimes extra-digestive symptoms such as fibromyalgia, interstitial cystitis, chronic fatigue syndrome, vulvodynia, overactive bladder, prostate pain syndrome, premenstrual syndrome and sexual dysfunction [1,7,12]. IBS does not occur on its own, but is usually grafted onto an existing gastrointestinal functional disorder such as dyspeptic syndrome or gastro-oesophageal reflux disease [1,7,8]. Several factors, notably psychological (anxiety, depression, somatization, hypochondriasis), are conducive to the onset of these conditions: lack of sleep, geographical location, alcohol consumption, lack of physical activity, a family history of IBS, food intolerance [1,2,12]. Physical and psychological stress is a major factor contributing to the etiology of IBS; a phenomenon that is greatly associated with students in general and medical students in particular who undergo an enormous academic load including healthcare professionals [1,17]. The exact mechanism is unclear, but it has been postulated that altered entral nervous system (CNS) responses to psychological and physical stressors result in colonic spasm, leading to the manifestation of IBS symptoms [22]. El Sharawy et al. [8] showed a significant association between anxiety, depression and IBS in a study of Egyptian students. It is well established that eating habits and dietary balance can play a very important role in determining the different aspects of IBS [8]. These factors are expected to be crucial for students, as they are generally less cautious about consumption. Reinforcing this hypothesis, a study of medical students at King Saud University, Saudi Arabia, found that nutritional factors were responsible for 15.5% of IBS symptoms [17].

Therapeutically, although no cure for IBS is known, treatments to control predisposing factors and relieve symptoms do exist, and include education, dietary adjustments, medication and psychological interventions [17]. This study seems to show an approximate result between self-medication, medical treatment and traditional treatment. For Sabaté [3], the doctor-patient relationship is essential to limit the frequent medical nomadism. It involves listening attentively and empathetically, reassuring the patient that the disease is benign, and setting reasonable therapeutic objectives [3]. Given the frequent relationship between IBS symptoms and factors such as diet, stress and psychological factors, it is important to pay particular attention to these, adopting all measures likely to reduce or even eliminate triggering factors. A variety of alternative/complementary therapies are available to IBS patients worldwide. In India, Ayurvedic medicine and in China, herbal medicine are widely available and frequently used for the treatment of IBS. However, it is difficult to judge their efficacy, as the concentration of active elements varies considerably depending on the extraction method used [7]. Oubaha et al. [4] demonstrated the usefulness of medicinal plants in relieving IBS symptoms. The use of peppermint (Mentha piperita) is a natural herbal product that is a "popular" remedy for IBS, recommended by the American Gastroenterological Association (AGA) [3,13]. Recently, a number of large clinical trials have shown that specific herbal therapies (peppermint oil and Iberogast®), hypnotherapy, cognitive behavioral therapy, acupuncture and yoga present better treatment outcomes in IBS patients [3]. These therapies are sometimes used as a complement to medical treatment, or sometimes on their own (in case of side-effects to medical treatment).

As the study was carried out in a group of medical students, the generalization of these results to all students or to the population as a whole could be biased due to the specificity of each socio-professional category. The advantage of this study is that it highlights a major factor, anxiety, contributing to the genesis of IBS.

Conclusion     

The prevalence of IBS among UAC students was 11.9%, of which the unspecified subtype was the most frequent, influencing their quality of life marked by absenteeism and work stoppage. Psychological disorders (anxiety), female gender, married status, personal history of sickle cell disease, soft drink consumption and Yorouba ethnicity were the main factors associated with IBS in our study. A general population survey using appropriate tools is needed to assess the prevalence of this condition in the population and the burden it represents for an under-informed population.

Competing interests     

The authors declare no competing interests.

Authors' contributions     

Study conception and design and data collection, analysis and interpretation: Aboudou Raïmi Kpossou and Benoît Kouwakanou. Manuscript writing: Aboudou Raïmi Kpossou, Benoît Kouwakanou, Comlan N'déhougbèa Martin Sokpon, Amahoni Charles Patrick Assogba. Manuscript revision: Kadiatou Diallo, Koffi Rodolph Vignon, Jean Séhonou. Study guarantor: Aboudou Raïmi Kpossou. All authors approved the final version of the manuscript.

Tables     

Table 1: distribution of irritable bowel syndrome by course and year of study, gender and age, marital status, ethnicity and religion of students (N= 536)

Table 2: distribution of irritable bowel syndrome according to students' personal and family history, frequency of physical exercise and sleep time (N= 536)

Table 3: distribution of irritable bowel syndrome according to students' eating habits and type of psychological disorder (N= 536)

Table 4: distribution of students according to the existence or not of food prohibitions, digestive and extra-digestive symptoms and quality of life among respondents to the Rome IV criteria, influencing factors (N= 64)

Table 5: results on the symptomatology of the various treatments received by students meeting the Rome IV criteria

References