The global prevalence of IBS among medical students and health care professionals is high (8–10). The prevalence of IBS in this study was found to be 14.5%. The finding is relatively consistency with findings among medical students in Saudi Arabia, Iran and health care professionals in Turkey where the prevalence of IBS was 13.7%, 12.6% and 13.5% respectively (9, 11, 12). On the contrary, studies in Asia; Pakistan and China reported high prevalence of IBS among medical students 28.3% and 33.3% respectively whilst prevalence of 28.4% among health care professionals. Anxiety, stress and lack of sleep being the primary triggers (9, 13, 14). In African medical students a relative comparable IBS prevalence to this study was evident in Nigeria and Sudan where the prevalence was 14.4% and 12.9% respectively (15). On the other hand, other studies among Nigerian medical student and nursing staff were consistency with some studies in Asia where the prevalence of IBS was as high as 26.1% and 45.2% in that order (16, 17).
The pathophysiology behind a high prevalence of IBS in medical students is constant nerve-racking environment to meet deadlines, examinations anxiety, long working and studying hours and less hours of sleep (8). Nevertheless, health care professionals are subjected to stressful environment due to the nature of the work and working environment (9). Although not fully defined, in genetically predisposed individual, stressful environment alter the micro biome-gut-brain axis that is key in IBS symptomatology. Stress, enhances the increase in systemic pro inflammatory cytokines and activates the hypothalamus pituitary adrenal axis. In turn, increases levels of corticotrophin releasing factor (CRF) from the hypothalamus that alter gut permeability causing infiltration of inflammatory cells, localized inflammation and mucosal edema. This results in changes in visceral neuromuscular function hence, IBS symptoms (18, 19).
IBS manifests in four major clinical subtypes as describe in literature review. Nevertheless, IBS shows a preponderance of females in their second and third decades of life. It was found that IBS-M subtype was common among MUHAS staff and students (56.3%) largely affecting females (59.9%). Similar findings have been reported in studies in Pakistan, Japan and China (2, 14, 20). While in Iranian medical students IBS-C was the predominant subtype (81.6%) (21).In African studies findings were similar to Pakistan, Japan and China where IBS-M was predominant (19.6% and 60.7%) (15, 17).
IBS has been shown to be associated with several factors as stipulated in literature review. In this study female gender, age below 25 years, alcohol intake and finalist students were independent predictors of IBS. In the same way, a study among medical students in China found that females were more affected than males (20). On the other hand, another study in China found that alcohol intake was significantly associated with symptoms of IBS (22). On the contrary, a study in Saudi Arabia among medical students IBS was predominant in males however, age and advanced academic levels were predictors of IBS (12). Studies in Turkey, Pakistan and Nigeria among health care professionals have displayed similar findings with studies among medical students in China where being a female was associated with IBS (9, 10, 17).
Evidence shows existence of CD among patients with IBS with variable burden across the globe. In this study, the prevalence of CD in patients with IBS based on the Rome IV criteria was 1.6%. Similarly, studies from Asia and Europe relieved comparable CD prevalence among IBS patients (23, 24). On the contrary, studies from Middle East have shown a higher prevalence of up to 9.6% (25–27). Likewise, similar findings were seen in Mexico where the prevalence of CD in IBS patients was 5.21% (28). Despite few studies in Africa, comparable findings to the middle East and North America were evident among Egyptian IBS patients where the prevalence of CD in IBS was found to be 8% (2). The low prevalence observed in study may be due to the fact that CD is uncommon in the Sub-Saharan Africa.
The manifestation of CD in IBS varies in different populations. In this study, CD was found in two patients with IBS-D subtype and one patient with IBS-M subtype. In the same way among Asians, CD has been seen commonly in patients with IBS-D subtype followed by IBD-M subtype and occasionally in IBS-C subtype (27, 29, 30). Conversely, in Iranian patients CD was found to be prevalent in IBS-U and less prevalent in the IBS-D subtype. A study in Africa has shown CD is common in IBS-D subtypes (24).
Furthermore, CD may present with bloating and weight loss, however, recent evidence has shown a decline in weight loss as a typical CD presentation (31). This study found that all CD patients had bloating and normal body mass index (BMI). In the same way, a study in India had similar findings where a normal mean BMI was evident in CD patients(23). Moreover, similar findings in terms of mean BMI were found in another study in Mexico (28). On the contrary, in Saudi Arabia it was found that patients with CD were underweight compared to those who were negative for CD where as in Jordan, CD patients were overweight (25, 30).
Current evidence shows a preponderance of atypical CD manifestation such as iron deficiency anemia (IDA), asymptomatic elevated liver enzymes and ESR. In this study, two CD patients had elevated ALAT with normal ASAT as well as ESR. IDA was evident in 1 CD patient. Similarly, studies in India and Jordan, IDA was non-significantly evident in the CD patients (23, 30). Another study, in India, a non- significant difference in HB between CD patients versus non CD patients with IBS was found (32). In Africa, Egypt, a significant lower HB was evident in CD patients with IBS but non-significant difference in liver enzymes and ESR among the two arms (2).
IDA in CD occurs as a result of loss of iron in the bowel enterocytes and mal-absorption of daily ingested iron (33). On the other hand, asymptomatic elevation in liver enzymes is due to increased intestinal permeability resulting in translocation of gut bacteria, kupffer cell stimulation, and production of tumor necrosis factor-α (TNF-α), pro-inflammatory cytokine, and reactive oxygen species, resulting in nonalcoholic steatohepatitis (NASH). In addition to, CD share common immunogenic factors and immunopathogenesis with other hepatobiliary disorders such as autoimmune hepatitis, primary biliary cirrhosis and primary sclerosing Cholangitis that may contribute to asymptomatic elevation in liver enzymes (34).
Study Limitations And Strength
It was a single centered study confined to MUHAS and MUHAS teaching hospital therefore; the observed prevalence rates cannot be generalized. CD serologic test can be falsely negative in IgA deficiency, for which this study did not screen. Response bias as study participants were required to complete an online survey.