The prevalence of IBS reported in this study was relatively high at 28.5%. This is higher than the IBS population prevalence in North America (12%), South America (21.0%), and Southeast Asia (7.0%) (1). The risk of having IBS was significantly higher among females than males, those who have a family history of IBS, those who were in the fifth–year, sixth-year, and third-year academic level, respectively, and those who were living in a private house (anxiety model only). IBS was significantly associated with depression, anxiety, and stress in our study. While the 28.5% prevalence rate of IBS among medical students in Jordan is relatively higher than that found in North America, South America, and Southeast Asia, but lower than reported by a Pakistani study using the Rome II criteria, 45.0% (16). The prevalence rate obtained in this study is similar to the prevalence of IBS among medical students at Hali University, Saudi Arabia (11) and to the prevalence of IBS among medical students in Pakistan Karachi (15). Our study result is higher compared to a study in China among university students at 7.85% (12), international research in eight different European countries at 11.5 percent (17), and a Lebanese study at five major universities in the Greater Beirut area, which was 20.05% (8). On the other hand, our study result is lower than a study in Saudi Arabia at King Abdul-Aziz University, Jeddah, which showed an IBS prevalence of 31.8 percent among medical students and interns (18). Inconsistency of reported prevalence rates may be due to many reasons, including s the diagnostic method used and the population studied.
The present study reported IBS-M as the predominant IBS subtype among all the other subtypes accounting for 42.5% of all cases. In agreement with our study, Costanian et al. described a similar finding in their study among medical students at five large universities in Beirut, Lebanon, with IBS-M accounting for 44.8% of those diagnosed with IBS (8). Naeem et al. also described a similar finding in their study among medical students in Pakistan, with IBS-M accounting for around 55% of those diagnosed with IBS (15). Furthermore, our study corresponded to what was found by Almutairi et al., who found that IBS-M was the predominant subtype among medical students in the Qassim region, Saudi Arabia, with 64.3% (6). On the other hand, our result is inconsistent with a study from Germany by Gulewitsch et al., in which IBS-D was higher than IBS-M (19). Another study conducted among medical students at Inner Mongolia Medical University, China, found that the predominant subtype was IBS-D in males and females (20).
Concerning IBS according to sex, our study showed that female students were more likely to suffer from IBS than male students, a finding consistent with most of available literature. Costanian et al. showed that female students were more likely to have IBS than males (8). Similarly, Shen et al. found that the prevalence of IBS was higher among Chinese female students than males (21). Also, in a study conducted in Germany, the prevalence of IBS was significantly higher among females than males (19). An explanation for this finding may be that females tend to be more emotional and more likely to suffer from depression, anxiety and stress. Other explanations include socio-cultural differences, differences in health-seeking behavior between men and women, or actual biological differences. On the other hand, our study result was inconsistent with a few studies including Jung et al. (22). a few reports from Mumbai, Europe, and North America (23).
The current work illustrates that sixth-year students and fifth-year students were more likely to develop IBS than first-year students. This result may reflect an increasing level of stress, anxiety, and depression with the increase of academic level and an increase in IBS. Our findings in this respect are consistent with Almutairi et al., who reported that advanced academic level was a risk factor for IBS. As the academic level increases, the odds of IBS also increase; those in the fifth year are 3.61 times more likely to have IBS than 1st years (6). Alaqeel et al. conducted a study among medical students at King Saud bin Abdulaziz University for Health Sciences in Riyadh. They reported that IBS was most prevalent among students in the final year, followed by students in the second year (13). On the other hand, our result was inconsistent with Almezani et al., who reported no statistically significant correlation between medical student educational level and irritable bowel syndrome (11).
We have found that a family history of IBS was associated with an increase in IBS. The odds of having IBS were two and half times higher in students who had a family history of IBS than students that did not have a family history of IBS. This study result agrees with the results obtained from most studies in the literature. A study conducted at the Hail University of Saudi Arabia showed a statistically significant association between family history of IBS and IBS prevalence (11). Almutairi et al. concluded that the family history of IBS was one of the significant predictors of IBS (6). On the contrary, our result was inconsistent with a study in Beirut, Lebanon, which showed that most of the respondents with IBS did not have a family history of IBS (8).
Bivariate analyses showed a statistically significant association between IBS and living situation (P = 0.041). IBS was most prevalent among students who lived at a private house, followed by those who lived in the school dormitory. Although on bivariate analysis, living situation was significantly related to IBS, this relationship disappeared when we controlled for confounders in the Stress level regression model and depression level regression model. The result of this study is consistent with most of the studies in the literature. Costanian et al. revealed that students living in private dormitories were three times more likely to suffer from IBS (8). Similarly, a study conducted in Saudi Arabia reported that the chance of having IBS was higher in those who were living alone away from their families (p = 0.005)(8).
Regarding sleep pattern, our study showed the association between daily sleeping hours and IBS was not statistically significant (P = 0.631). Similarly, Almutairi et al. reported that daily sleeping hours did not influence the risk of IBS. P = 0.546 (6). Another study explored the relation between overnight calls and IBS and found no significant relationship (24). However, our result was inconsistent with a study performed on nursing and medical students in Japan, showing that IBS students had bedtime later than non-IBS students (16).
Almutairi et al. reported that eating habits did not influence the risk of IBS P = 0.634 (6). Similarly, the current study illustrated that the prevalence rate of IBS among medical students at JUST was not related to eating habits.
Concerning physical activity, Costanian et al. found that students who reported regular practicing of physical activity had a significantly lower IBS prevalence than others (8). However, our study showed no protective effect of physical activity on the prevalence rate of IBS.
Our study showed no association between smoking status and IBS prevalence; this was consistent with what was found by Ibrahim et al. who revealed an insignificant association between smoking and IBS (18).
Our study showed that IBS prevalence was highest among students with a family income of more than 1500JD (US $ 2200). However, this association disappeared when we controlled for confounders in the regression models. The result of this study, although not significant, is similar to what was found by Costanian et al. who reported that IBS was significantly higher among students with higher levels of income (8).
Our study revealed that depression, anxiety, and stress were significantly associated with IBS. The results of this study are consistent with most of the studies in the literature. a Chinese study reported that the anxiety and depression score for IBS students was significantly higher than for those without IBS. 65.9% of IBS patients believed that discomfort is related to a bad mood (12). A study performed in Saudi Arabia demonstrated a significant impact on IBS prevalence by depression (p = 0.042). Students with morbid depression levels had a higher prevalence of IBS compared with those with borderline depression. This study showed that the prevalence of IBS was higher in students with morbid anxiety levels than those with borderline anxiety levels. However, this was not statistically significant (6). Differences between our study and this study regarding anxiety may be explained by differences in the diagnostic tool used to determine the degree of depression and anxiety; we used the DASS-21 scale, but Almutairi et al. used the Hospital Anxiety and Depression Scale (HAD) which is a different tool. In another study conducted among medical students at Inner Mongolia Medical University, China, the researcher reported that Students with anxiety and depression had almost twice as high a prevalence of IBS as those without anxiety and depression; this finding is congruent with our finding (20). Moreover, a study conducted at King Saud bin Abdulaziz University for Health Sciences in Riyadh, Saudi Arabia, revealed a significant association between anxiety and IBS (p = 0.039) (13). Also, Ibrahim et al. reported that (41.9%) of medical students with IBS were diagnosed as having a morbid level of depression compared to normal students (31.5%) in Jeddah (18).
The present study is that the first to use Rome IV criteria as a diagnostic tool among Jordanian medical students. We assessed the effect of many factors on IBS prevalence using an adequate sample size. However, our study had three limitations. First, this study was conducted without consideration of red flags symptoms; other conditions that have symptoms that may mimic IBS were not checked. Therefore, our results had the potential to overestimate the prevalence of IBS. Second, our study was based on self-reported data. Third, due to the cross-sectional nature of our study, it is difficult to establish a temporal sequence from cause to effect. Thus, we can’t know which started first, depression, anxiety, and stress or IBS.
Research on IBS in Jordan is very scarce. There is a need for research on the economic impact of IBS and the extent to which IBS influences the quality of life of the different sectors of the population.
IBS prevalence among medical students at JUST is 28.5%, which is high compared with other studies. IBS-M is the most predominant subtype constituting 42.5% of cases. Sex, family history of IBS, academic level, residence, stress level, depression level, and anxiety level are the main predictors of IBS.
We recommend conducting counseling sessions to help medical students, particularly females cope with stressful conditions, manage their time, and improve their quality of life. A stress management course may be useful in this regard. We also recommend increasing the awareness of physicians to the high risk of IBS in medical students.