# Information on the fight or flight response and ibs



## eric (Jul 8, 1999)

FYI: "The Fight or Flight in Irritable Bowel Syndrome" Overactivation Linked To Predominance of Diarrhea Symptoms An intense, powerful "fight-or-flight" response comes in handy when you're running away from a hungry tiger, but it could be the source of misery for people with certain digestive disorders. The chronic gastrointestinal distress of Irritable Bowel Syndrome (IBS) has been linked to "miscommunication" between the gut and the brain. Although it's still unclear just exactly how a glitch in gut-brain interaction sparks specific symptoms, a recent study has uncovered one important potential mechanism in a subgroup of patients. In patients with IBS who regularly experience diarrhea, pain, and other symptoms soon after eating, an "overdominant" sympathetic nervous system - signaled in part by the heightened release of the STRESS hormone cortisol after eating - may play a key role in triggering their symptoms. Researchers evaluated a group of 24 patients with IBS and a group of healthy controls, measuring their salivary cortisol levels, their heart rates, and their heart rate variabilities at different times of the day. Compared to the controls and to IBS patients with constipation, IBS patients with chronic food-induced diarrhea "demonstrated a significant increase in cortisol" soon after eating - with levels nearly doubling. This subset of patients also showed a more dominant sympathetic nervous system response, as evidenced by their heart rate variability ratios. The sympathetic nervous system tends to mobilize the body's stimulatory "fight-or-flight" response. Normally it's kept in check by the dampening effects of the parasympathetic nervous system. In patients with IBS with diarrhea, however, this muting response (mediated by the vagus nerve) appears weaker - a condition called "vagal withdrawal." "Notably, this vagal withdrawal was significantly associated with patients' reports of gastrointestinal symptoms," the researchers pointed out. These included bloating, abdominal pain, indigestion, and heartburn. A heightened, stimulatory stress response, characterized by overactivation of both the HPA-axis and sympathetic nervous system, may be triggered by "abnormal ascending feedback from the gut," the researchers speculated.Am J Gastroenterol 2001 Feb;96(2):460-6 Diarrhea- and constipation-predominant IBS patients differ in postprandial autonomic and cortisol responses. Elsenbruch S, Orr WC. Institute for Medical Psychology, University Clinic of Essen, Germany. OBJECTIVE: As the primary link between brain and gut, autonomic and endocrine dysfunction may play a role in the pathophysiology of the irritable bowel syndrome (IBS). The aim of this study was to assess autonomic, endocrine, and symptomatic responses to food intake in diarrhea-predominant and constipation-predominant IBS patients, compared to normals. METHODS: Twelve women with diarrhea-predominant or alternating IBS (IBS-D), 12 women with constipation predominant IBS (IBS-C), and 20 healthy women participated. GI symptoms, saliva cortisol concentration, heart rate, and heart rate variability were assessed at baseline and after a meal. Spectral analysis of heart rate variability was used as a measure of the sympathovagal regulation of the heart rate. RESULTS: Both groups of IBS patients showed a significant postprandial increase in GI symptoms. IBS-D showed a significant increase in the low frequency/high frequency band ratio and a decrease in the high frequency band power during the first postmeal period, which was significantly different, not only from controls, but also from IBS-C. IBS-D also showed a significant postprandial increase in cortisol, which was not evident in controls or IBS-C. There was a significant correlation between the vagal response and the postprandial increase in GI symptoms in IBS-D (r = 0.6, p < 0.05). CONCLUSIONS: These findings support the notion that the IBS symptom groups are characterized by different physiological responses to visceral stimuli, and point to a role of autonomic pathways in IBS symptomatology. PMID: 11232691 [PubMed - indexed for MEDLINE] J Endocrinol Invest 2001 Mar;24(3):173-7 Related Articles, Books, LinkOut Actual stress, psychopathology and salivary cortisol levels in the irritable bowel syndrome (IBS). Patacchioli FR, Angelucci L, Dellerba G, Monnazzi P, Leri O. Department of Physiology and Pharmacology V. Erspamer, Medical Faculty, University of Rome La Sapienza, Italy. Although irritable bowel syndrome (IBS) can be considered a biopsychological disorder in which an association between life stress and physiological changes leading to bowel irregularity is present, there is a lack of data concerning possible modifications of the adrenal function during the disease. The aim of the present study was to measure biological and psychological variables related to the activity of the hypothalamo-pituitary-adrenal axis in IBS patients compared to healthy subjects. Cortisol was measured in the saliva (obtained by a stress-free, non invasive collection procedure) of 55 IBS outpatients and 28 matched controls. Moreover, each subject completed the following self-administered questionnaires: the Rome Burnout Inventory (RBI) in its physical (RBI-PE) and emotional-mental exhaustion (RBI-EME) components, Beck Depression Inventory, State and Trait Anxiety Inventory (STAI), Perceived Social Support Scale (PSSS) and a Scale for the Assessment of Perceived Actual Work-Non Work Stress. Compared with controls, IBS subjects showed significantly higher levels of cortisol in the morning and lower in the evening, while they maintained the physiological circadian fluctuation (i.e. cortisol morning level higher than in the evening). Moreover, IBS patients presented a significant difference from controls in RBI-PE scores, which confirms the presence of fatigue, a symptom frequently reported by the patients. Compared with controls, no differences were found in IBS patients with respect to other psychological parameters. These findings suggest a dysregulation of the adrenal activity in IBS patients. The results may be relevant considering that changes in cortisol levels have been shown to be sensitive indicators of psychosocial stress and coping patterns in both laboratory and life situations. PMID: 11314746 [PubMed - indexed for MEDLINE] "What is Irritable Bowel Syndrome and how do I knowif I have it?Irritable Bowel Disease or IBS is an exaggerated formof the normal digestive processes. Our digestivesystem--the stomach, small and large bowel, liver, andgall bladder-- helps us to utilize the food we eat. Withthe kidneys, it controls fluid balance. Digestion, likebreathing, is a twenty-four-hour-a-day process and oursystem must respond to all the little ï¿½insultsï¿½ we give it. Most of us understand terms like butterflies in thestomach and gut wrenching. These familiar sensationsoccur because the digestive system has both a muscularand a hormonal component for moving fluids through thesystem. When there is stress like the classic fight orflight response, the whole digestive process speeds upleading to cramping and nausea. Vomiting and diarrheamay also occur. The faster process during stress can behelpful at these times because the body can divert itsenergy to more urgent needs. However, too strong aresponse will produce difficulties like fluid imbalanceand subsequent weakness. Not only do people with IBS have an exaggeratedresponse to emotional stress; they also have anexaggerated response to normal digestion and may feelbloated and crampy even when not stressed. If the bowelmuscles are working inefficiently there can be bloatingbehind the cramped portion of bowel causing pain.Further, if the digestive juices are slowed in their transit,constipation occurs. If the digestive process is speededup, mucous can be passed along with a semisolid bowelmovement. Another exaggerated response is a rush to thebathroom right after eating, which occurs because eatingstimulates the entire gut. Since transit time of digestivejuices varies between people and can be up to 48 hours,it is often difficult to know if a recently consumed foodis causing a problem. Digestion of beans and othercomplex carbohydrates requires gas-producing bacteria,leading to increased gas. Caffeine, alcohol, and dairyproducts can cause problems, too.It is best to seek a medical evaluation if you are havingdigestive upset. You should not assume it is IBS. Colitis,diverticulitis, malabsorbtion, and other conditions canall mimic aspects of IBS. Medications can be used tosmooth the process of IBS and you can do your part byeating a regular diet containing plenty of fruits,vegetables, and whole grain cereals. You should avoidexcess caffeine and alcohol and exercise regularly --these affect transit time. Reduction of excessive stress isalso very helpful. Only those who have lactoseintolerance need avoid dairy products. Your health careprovider is a good resource for more information on IBStreatment. For more information, visit the web site of theNational Institute of Diabetes and Digestive Diseases at: http://www.niddk.nih.gov/ (Click on Health Informationand Education).Dr. Mary HackerStudent Health Service Physician" http://www.uiowa.edu/~shs/HILog/q_illness12.htm Do women differ from men in the fight or flight response. http://www.med.ucla.edu/ndp/Newsletters/Summer01Gender.htm


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