595
Fig. 5. Stress as exacerbatingfactor in the pathogenesis ofinflammatory bowel disease.There is a strong evidencethat the exposure to stressmay lead to the exacerbationof inflammatory boweldisease. The exactmechanism responsible forthis phenomenon is still notfully understood, but thestress leads to the shift towardincreased expression ofproinflammatory cytokines in
colonic mucosa.
Fig.6. Disruption of brain-gut-microbiota axis as thepotential pathophysiologicalcause of irritable bowelsyndrome. Stress isassociated with thedevelopment of irritablebowel disease. Theactivation of brain-gut axisleads to the changes invisceral sensitivity, changesin the release ofgastrointestinal hormonesand neurotransmitters,increased expression andrelease of proinflammatorycytokines, changes in thegastrointestinal motility andgut microbiota.
Among important risk factors is genetic susceptibility andchronic stress (life events) while the key trigger factors includepsychosocial factors and exposure of the gut to infections oroveruse of antibiotics leading to negative alterations in gut flora.There is a strong evidence of the putative role of gut microbiotain the disturbance of brain-gut axis in IBS. Later during thecourse of this disease due to anxiety and the upregulation ofimmune system an irreversible state of self-perpetuation takesplace (42).
The definition of IBS is based on the so called Rome IIIcriteria which characterize IBS (43) if: recurrent abdominal painor discomfort for ≥3 days per month in the last 3 months,associated with ≥2 of the following:
-improvement of symptoms with defecation;
-onset associated with a change in stool form (appearance);
The pathogenesis of IBS is multifactorial and in IBSpatients a profound dysregulation of the brain gut axis takesplace (Fig. 6). Among the observed gut disorders, the mostimportant is a visceral hypersensitivity. In addition, release ofimportant neuropeptides, up-regulation of immune system (lowlevel inflammation), changes in motility, behaviour, endocrinefunctions and microbiota occur (44). IBS is classified intodifferent subtypes based on the predominant symptoms: IBS-D,IBS-C, IBS-M (44).
Diagnostic approach to the potential IBS patient includesobtaining a full medical history, physical examination,laboratory testing and operative diagnostic procedures. Withconcerns to taking the medical history, the physician should