The articles relevant to the topic were found using the below-mentioned databases and search strategies (Table 1 and Table 2).

Eligible review articles were identified after screening and applying the inclusion/exclusion criteria.

Cause of stress, otherwise known as “stressors,” are plenty in number in a student’s life. Let it be in school or college; these stressors will play a part in a student’s body, thoughts, and feelings. Gomathi et al. mention that academic, emotional, and health-related stressors are the three types of stressors [11]. “Frequency of exams,” “academic burden,” and “time management” are all part of the academic realm. The psychological domain, on the other hand, was primarily concerned with “future fears,” “excessive parental expectations,” “anxiety,” and “working with members of the opposing gender.” “Irregular eating habits,” “lack of exercise,” and “lack of a nutritious diet” were among the health-related domains [11]. Especially students living away from their families tend to skip meals or eat healthy [11].

Similarly, a study conducted in 2013 mentions that the main stressors among students are linked to academic performance and the psychosocial realm [2]. This study also mentions that Unsuitable teaching methods, an uncomfortable college study atmosphere, and the worry of failing exams are all possible sources of stress for college students [2]. Healthy eating habits, a positive mindset, and physical exercise are needed to perform well in college and keep stress at bay.

The stressors are explained in Figure 2.

In 2014, El Ansari et al. reported that the frequency of symptoms increased with perceived stress [4]. Based on quartile, perceived stress was divided into four levels.

On a scale of one to four, the first quartile (Q1) had the lowest stress and symptoms and the fourth quartile (Q4) had the greatest. Students with Q4 level of stress, experienced almost 2 - 3 gastrointestinal symptoms more than Q1 [4]. Likewise, a cross-sectional study conducted in 2011 also noted a significant relationship between the increasing level of perceived stress and the number of gastrointestinal symptoms [5]. Seemingly gender had a role in the level of stress. In a recent study, female students reported having higher anxiety levels and specific symptoms such as inflammatory bowel syndrome [7]. In contrast, Rahman et al. specified in their study that males are exposed to higher levels of stress than females [14]. Since the study conducted in 2013 had a total of 650 participants and the study conducted years later in 2020 had only 81 participants, males could be more prone to high levels of stress as they have financial responsibility and need to finish their studies at an optimum time [7] [14].

Nevertheless, stress needs to be controlled in both males and females to avoid experiencing displeasing symptoms. And interestingly, with increasing age, the level of stress decreases [4] [9]. Younger students are believed to experience more stress than older students.

The gastrointestinal symptoms (Figure 3) can be classified as abdominal pain, esophageal, upper dysmotility, and bowel symptoms [7]. Esophageal symptoms

included dysphagia and heartburn, upper dysmotility symptoms: nausea, vomiting, early satiety, post-meal fullness in the abdomen, and bloating. Bowel symptoms are diarrhea, constipation, the urgency of stool, and stool incontinence [7]. According to the cross-sectional study conducted by Jahan et al., the most common symptoms experienced by students were post-meal fullness (34.6%), bloating (37%), abdominal pain (28.4%), diarrhea (7.4%), and constipation (28.4%) [7]. In addition, another study mentions the common symptoms as postprandial fullness (91.3%), bloating (88.9%), abdominal pain (87.8%) and diarrhea/constipation (84.7%) [5]. Changes in stool frequency during a stressful time were also another observation made about gastrointestinal habits during stressful conditions [9].

It was also observed that females and male students experienced different symptoms. Females usually complained of inflammatory bowel syndrome, and males complained of symptoms related to gastroesophageal reflux disease [7] [12]. A study conducted in 2020 states that inflammatory bowel syndrome was 21% higher in females [7]. In contrast, Awadalla et al. report in their study that gastroesophageal reflux disease was higher in males [12]. The cause of reflux is that when exposed to stress, there is an increased release of gastric acid and a slow pace of gastric emptying [14].

In the study by Chu et al., health complaints of students from German and Chinese universities were compared. Similarly, Ansari et al. compared the students from the UK and Egypt [4]. Both of these studies compared a country from Western Europe and Asia. The studies indicate that several factors like sociographic, lifestyle, religious beliefs, and cultural differences could contribute to the stress level in university students [13]. In addition, the nature of the study in the higher education system varies greatly between Asians and western countries [4]. In Egypt, traditionally, students enter universities right after finishing high school, and on the other hand, high school students in the UK take a gap year before applying for colleges [4]. This practice in the west helps students relax and catch their breath instead of rushing into college and adding to their stress levels. However, students of the west generally were older, consumed more alcohol, used illicit drugs, and smoked more than students of Asia [4] [13]. All these external factors could increase the chances of triggering certain health complaints, including gastrointestinal symptoms. Chu et al. reported that Chinese students complained of gastrointestinal symptoms more often than German students who had psychological symptoms [13]. It was also noted that students with a higher BMI had fewer gastrointestinal complaints among the Chinese students but had no significant association among the Germans [13]. It’s evident through these studies that Asian students have higher levels of stress and complain more about gastrointestinal symptoms than the students of the west.

One of the main limitations of the included studies is that all the studies are cross-sectional studies; hence no causal relationship can be derived. The stress reported by the students could have been a result of prevailing symptoms or vice versa, where the symptoms add to students’ stress levels. Hence more clinical research is required to support this relationship. Although it was required that articles included being only specific to stress and gastrointestinal symptoms, some studies mentioned gastrointestinal symptoms under a general group termed as health complaints.