Abstract
AIM: To investigate the morbidity of functional bowel disorders (FBD) under military stress conditions in order to lay foundations for the prevention and treatment of this disease.
METHODS: Four hundred and fifty-seven soldiers who were assigned to specified services and 471 soldiers who were assigned to routine services were enrolled using cluster sampling, with the latter as a control group. They were surveyed using the Rome III FBD standard questionnaire. The FBD symptom questionnaire included FBD-related symptoms, severity, duration or attack time, and accompanying symptoms.
RESULTS: The morbidity of the military stress group (14.6%) was significantly higher than in the control group (9.98%) (χ2 = 4.585, P < 0.05). The incidence of smoking, abdominal pain and acid regurgitation (χ2 = 4.761, P < 0.05) as well as the ZUNG anxiety/depression scores (χ2 = 7.982, P < 0.01) were also significantly higher in the military stress group compared with the control group. ZUNG anxiety (χ2 = 11.523, P < 0.01) and depression (χ2 = 5.149, P < 0.05) scores were higher in the FBD group compared with the non-FBD group. The differences in the ZUNG self-rated anxiety and depression scales between the 2 groups were statistically significant (χ2 = 14.482, P < 0.01 and χ2 = 6.176, P < 0.05).
CONCLUSION: The morbidity of FBD was higher under military stress conditions.
Keywords: Military stress, Functional bowel disorders, Soldier, Self-rating anxiety, Depression scale
INTRODUCTION
Functional bowel disorders (FBD) is the generic term for disorders of bowel motor and secretary function without organic changes, which are diagnosed according to symptoms after the exclusion of lesions such as inflammation, infection, tumor and other structural disorders[1-3]. FBD includes 5 diseases, irritable bowel syndrome, functional abdominal bloating, functional constipation, functional diarrhea and unspecified functional bowel disorder. FBD are common clinical diseases which significantly affect the quality of patients’ lives and incur considerable medical costs. A large number of studies have proved that stress is the primary induction factor of FBD. Military stress is the emotional reaction of soldiers under military conditions, and mainly manifests as a state of tension[4,5]. There are few studies regarding the effect of military stress on FBD[6], and thus this study investigated the effects of stress by comparing FBD morbidity in soldiers conducting specialized operations with those carrying out regular tasks.
MATERIALS AND METHODS
Objects
Five hundred armed soldiers (mean age 20.7 ± 1.9 years) who were transferred from one province to another in China between April 2009 and May 2010 to handle emergencies were classified as the military stress group; Five hundred armed soldiers (mean age 20.14 ± 1.65 years) from the same province who conducted routine tasks were classified as the control group. All of the soldiers were male and garrisoned in the local area at least 1 year. Both groups were comparable in age, weight, height, the length of military service, education background, duty time, training time and garrison time.
Methods
Questionnaire: The FBD symptom questionnaire including FBD-related symptoms, severity, duration or attack time, and accompanying symptoms, was made with reference to Rome III FGIDs functional gastrointestinal disorder standard questionnaire[7], and in combination with the practical conditions of the soldiers in the Chinese People’s Armed Police. Psychological factors were investigated using the ZUNG Anxiety Scale and ZUNG Depression Scale.
Quality control of the questionnaire: The questionnaires were distributed according to lists of soldiers by responsible persons in every unit, and were filled in immediately after professional staff gave instructions and answered questions. All questionnaires were checked by a specially designated person after their return. The response rate and acceptance rate were 95.20% (476/500) and (452/476), respectively, in the military stress group, and 96.20% (481/500) and (471/481), respectively, in the control group.
Statistical analysis
The results were input into Epi Info 2003 software to establish data library and analyzed by SPSS18.0 statistical software; the χ2 test was performed on categorical data. It was statistically significant at P < 0.05.
RESULTS
Morbidity of FBD
The rates of FBD in the military and control groups were 14.60% (66/452) and 9.98% (47/471), respectively. The difference between the two groups was statistically significant (P < 0.05, Table 1).
Table 1.
Comparison of morbidity and prevalence of primary symptoms of functional bowel disorders in the military stress and control groups n (%)
| Military stress group | Control group | χ2 | P | |
| Disease name | ||||
| Irritable bowel syndrome | 28/452 (6.19) | 16/471 (3.40) | 3.972 | < 0.05 |
| Functional abdominal bloating | 0/452 (0.00) | 0/471 (0.00) | > 0.05 | |
| Functional constipation | 23/452 (5.09) | 20/471 (4.25) | 0.443 | > 0.05 |
| Functional diarrhea | 9/452 (1.99) | 8/471 (1.70) | 0.108 | > 0.05 |
| Non-specific functional bowel disorder | 6/452 (1.33) | 3/471 (0.64) | 1.135 | > 0.05 |
| Total | 66/452 (14.6) | 47/471 (9.98) | 4.585 | < 0.05 |
| Primary symptom (No. of person with symptoms) | ||||
| Nausea | 133/452 (29.42) | 74/471 (15.71) | 24.931 | < 0.01 |
| Vomiting | 74/452 (15.71) | 53/471 (11.25) | 5.849 | < 0.05 |
| Abdominal distension | 145/452 (32.08) | 103/471 (21.87) | 12.230 | < 0.01 |
| Acid regurgitation | 113/452 (25.00) | 64/471 (13.59) | 19.329 | < 0.01 |
| Heartburn | 61/452 (13.50) | 43/471 (9.13) | 4.397 | < 0.05 |
| Foreign body sensation in throat | 85/452 (18.81) | 78/471 (16.56) | 0.800 | > 0.05 |
| Substernal pain | 70/452 (15.49) | 47/471 (9.98) | 6.312 | < 0.05 |
| Hiccough | 135/452 (29.87) | 82/471 (17.41) | 19.899 | < 0.01 |
| Food regurgitation | 101/452 (22.34) | 61/471 (12.95) | 14.068 | < 0.01 |
| Abdominal pain | 31/452 (6.86) | 13/471 (2.76) | 8.483 | < 0.01 |
| Constipation | 142/452 (31.42) | 98/471 (20.81) | 13.492 | < 0.01 |
| Diarrhea | 121/452 (26.77) | 86/471 (18.26) | 9.602 | < 0.01 |
| Encopresis | 15/452 (3.32) | 9/471 (1.91) | 1.808 | > 0.05 |
Prevalence of primary symptoms
There were 14 primary symptoms of FBD in the questionnaire. Individuals in the sampled populations could have one or more gastrointestinal symptoms. The prevalence of the primary symptoms is presented in Table 1.
Comparison of food habits and intake in soldiers with or without FBD
The food habits of soldiers with FBD were significantly different from those without FBD (P = 0.000-0.001). The occurrence of bad habits such as engorgement, being particular about food, omophagia, taking cold drinks, eating hot or spicy food, drinking tea and coffee was more frequent in the FBD group than in the non-FBD group (Table 2); the proportion of soldiers who had few or no bad food habits was smaller in the FBD group compared with the non-FBD group (P = 0.000-0.001); the proportion of soldiers who ate a lot of vegetables and fruit was smaller in the FBD group compared with the non-FBD group, while the proportion of soldiers who ate few vegetables and fruit was higher in the FBD group compared with the non-FBD group (P = 0.000); the proportion of soldiers who ingested many dairy products was higher in the non-FBD group compared with the FBD group, while the proportion of soldiers who ingested few dairy products was smaller in the FBD group compared with the non-FBD group (P = 0.000); the proportion of soldiers who drank coffee was higher in the FBD group compared with the non-FBD group, while the proportion of soldiers who drank tea was smaller in the FBD group compared with the non-FBD group (P = 0.000-0.001).
Table 2.
Food intake of soldiers with and without functional bowel disorders n (%)
| Food habit | Much | Moderate | Less | Little or not | Total |
| With functional bowel disorder | |||||
| Engorgement | 10 (15.9) | 21 (32.5) | 20 (31.1) | 13 (20.3) | 64 (100) |
| Omophagia | 6 (8.8) | 10 (15.7) | 23 (34.9) | 26 (40.1) | 65 (100) |
| Particular about food | 12 (18.9) | 19 (29.4) | 15 (22.8) | 20 (30.3) | 66 (100) |
| Cold drinks | 14 (20.6) | 22 (33.3) | 20 (30.6) | 10 (15.2) | 66 (100) |
| Spicy food | 22 (33.4) | 21 (32.1) | 17 (26.3) | 5 (7.7) | 65 (100) |
| Dairy products | 20 (30.9) | 24 (37.2) | 15 (24.1) | 6 (9.3) | 64 (100) |
| Vegetables | 17 (27.6) | 33 (51.7) | 12 (19.2) | 1 (1.6) | 63 (100) |
| Fruit | 14 (22.6) | 26 (39.5) | 18 (28.4) | 7 (10.8) | 65 (100) |
| Without functional bowel disorder | |||||
| Engorgement | 3 (5.1) | 10 (16.3) | 18 (29.2) | 29 (48.3) | 60 (100) |
| Omophagia | 3 (5.8) | 6 (10.4) | 15 (24.9) | 35 (59.3) | 59 (100) |
| Particular about food | 5 (8.0) | 10 (17.8) | 11 (19.8) | 32 (55.1) | 58 (100) |
| Cold drinks | 7 (11.6) | 16 (26.3) | 17 (28.6) | 21 (34.4) | 61 (100) |
| Spicy food | 10 (16.4) | 16 (27.1) | 15 (25.8) | 19 (31.7) | 60 (100) |
| Dairy products | 16 (25.9) | 23 (37.2) | 12 (19.1) | 11 (17.7) | 62 (100) |
| Vegetables | 24 (37.4) | 28 (43.7) | 6 (9.2) | 5 (7.9) | 63 (100) |
| Fruit | 22 (34.6) | 24 (37.5) | 12 (18.7) | 6 (9.4) | 64 (100) |
Comparison of the ZUNG self-rating anxiety and depression scales
The proportion of soldiers who had a score > 40 in the ZUNG self-rating anxiety scale was higher in the military stress group (11.97%) than in the control group (5.52%), and was statistically significant (P < 0.01). The proportion of soldiers who had a score > 40 in the ZUNG self-rating depression scale was also higher in the military stress group (68.29%) than in the control group (58.60%), and was statistically significant (P < 0.05).
DISCUSSION
Military stress[8,9] is a type of emotional reaction appearing in soldiers under military conditions, and mainly manifests as tension. Military stress can be considered as a kind of stimulated or emotional state[10,11]. Military stress cannot be simplistically considered as a negative reaction. It can be understood as a psychological problem only when stress induces changes in the cognition, emotions and behavior of soldiers to severely reduce their efficiency in military missions, and is mainly manifested by an inability to take part in daily military training, to adapt to the military environment or to join in fighting[12,13].
In recent years, more studies have focused on the effect of stress on gastrointestinal function[14], but few have paid attention to the effects of military stress on gastrointestinal function[15,16]. The results in this study suggested that FBD was significantly higher in the military group (14.60%) compared with the control group (9.98%). Meanwhile, the rates of smoking, abdominal pain, and acid regurgitation, and the ZUNG anxiety and depression scores were also significantly higher in the military group compared with the control group. The increased incidence of FBD under military stress might be due to the dual regulatory effects of the autonomic nervous system and the endocrine system on the movement and secretion of the alimentary tract, which are directly or indirectly affected by the central nervous system[17,18]. The anatomical structures of the nervous and endocrine system overlap with that of the emotional center[19,20], thus after tension and emotional changes induced by military stress conditions arrive at the emotional center, the gastrointestinal regulatory center will also be excited, and therefore, gastrointestinal discomfort will likely occur or be aggravated[21,22].
It has been reported[23] that there are significant differences between individuals in the length of time psychological stress is sustained. Overall, although a psychological stress reaction may be alleviated within 10 d in about 85% soldiers, it persists in about 15% soldiers after 10 d. The following measures should be adopted to deal with the increased morbidity of FBD induced by military stress: a focus on daily training activity[24,25], with simulation of various duty environments, and enhanced quality of psychological and mental preparation for emergencies; the soldiers should actively take part in the handling of an emergency situation, have a specific daily schedule with adequate rest periods, and be given medical treatment if necessary. Non-combat casualties resulting from illness will be decreased and should guarantee that military duties will be better accomplished[26].
Overall, FBD is an old problem, but there are still areas in the pathogenesis of the disease to explore, and which may involve a wide range of research, including cell biology, neurophysiology, immunology, endocrinology, behavior and other fields of medicine and psychology. Linking the clinical problem with stress may directly lead to a clinical benefit for all patients.
COMMENTS
Background
Functional bowel disorders (FBD) is a generic name for disorders in bowel motor and secretary function without organic changes, and is diagnosed according to symptoms after the exclusion of lesions such as inflammation, infection, tumor and other structural disorders. It is a common clinical disease which significantly affects the quality of patients’ lives and incurs medical costs. A large number of studies have shown that stress is the primary induction factor of FBD.
Research frontiers
There are few studies of the effect of military stress on FBD, and thus this research tried to investigate these effects through comparing the morbidity in soldiers conducting specialized tasks with those undertaking regular tasks.
Innovations and breakthroughs
Four hundred and fifty-seven soldiers who were assigned to specified services and 471 soldiers who were assigned to common services were enrolled using cluster sampling, with the latter as the control group, and then they were surveyed according to the Rome III FBD standard questionnaire.
Applications
To provide foundations for the prevention and treatment of this disease, authors investigated the morbidity of FBD under military stress conditions.
Terminology
FBD: Disorders of bowel motor and secretary function without organic changes, diagnosed according to symptoms after the exclusion of organic lesions.
Peer review
Overall, this is an interesting study which shows clearly that the morbidity of FBD was higher under military stress conditions.
Footnotes
Peer reviewers: Javier San Martin, Chief, Gastroenterology and Endoscopy, Sanatorio Cantegril, Av. Roosevelt P 13, Punta del Este 20100, Uruguay; Ted Dinan, Professor, Department of Psychiatry and Alimentary Pharmabiotic Centre, University College Cork, Cork C1, Ireland
S- Editor Gou SX L- Editor Cant MR E- Editor Zheng XM
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