No abstract

These results support the hypothesis that both fecal microbiota and organic acids are altered in IBS patients. A combination of Veillonella and Lactobacillus is known to produce acetic and propionic acid. High levels of acetic and propionic acid may associate with abdominal symptoms, impaired QOL and negative emotions in IBS.

Irritable bowel syndrome (IBS) is a common chronic disorder seen in gastroenterology and primary care practice. It is characterized by recurrent abdominal pain or discomfort associated with disturbed bowel function. It is a heterogeneous disorder with varying treatments, and in this regard physicians sometimes struggle with finding the optimal approach to management of patients with IBS. This disorder induces high health care costs and variably reduces health-related quality of life. IBS is in the class of functional gastrointestinal disorders, and results from dysregulation of central and enteric nervous system interactions. Psychosocial factors are closely related to their gut physiology, associated cognitions, symptom manifestations and illness behavior. Therefore, it is important for the physician to recognize the psychosocial issues of patients with IBS and in addition to build a good patient-physician relationship in order to optimize treatment. This review focuses on the interaction between psychological and physiological factors associated with IBS by using a biopsychosocial model. In this article, we describe (1) the predisposing psychological features seen in early life; (2) the psychological factors associated with life stress, the symptom presentation, and their associated coping patterns; (3) gut pathophysiology with emphasis on disturbances in motility, visceral hypersensitivity and brain-gut interactions; and finally (4) the clinical outcomes and effective treatments including psychotherapeutic methods.

The prevalence of IBS was higher among nursing and medical students, and further interventional studies are needed to improve IBS symptoms.

Objectives Irritable bowel syndrome (IBS) patients show pain hypersensitivity and hypercontractility in response to colonic or rectal distention. Aims were to determine whether predominant bowel habits and IBS symptom severity are related to pain sensitivity, colon motility, or smooth muscle tone. Methods 129 patients classified as IBS with diarrhea (IBS-D, n=44), IBS with constipation (IBS-C, n=29), mixed IBS (IBS-M, n=45) and unspecified IBS (IBS-U, n=11) based on stool consistency, and 30 healthy controls (HC) were studied. A manometric catheter containing a 600-ml capacity plastic bag was positioned in the descending colon. Pain threshold was assessed using a barostat. Motility was assessed for 10 min with the bag minimally inflated (individual operating pressure or IOP), 10 min at 20 mmHg above the IOP, and for 15-min recovery following bag inflation. Motility was also recorded for 30 min following an 810-kcal meal. Results Compared to HC, IBS patients had lower pain thresholds (medians: 30 vs. 40 mmHg, p<0.01), but IBS subtypes were not different. IBS symptom severity was correlated with pain thresholds (rho=-0.36, p<0.001). During distention, the motility index (MI) was significantly higher in IBS compared to HC (909±73 vs. 563±78, p<0.01). Average barostat bag volume at baseline was higher (muscle tone lower) in HC compared to IBS-D and IBS-M but not compared to IBS-C. The baseline MI and bag volume differed between IBS-D and IBS-C and correlated with symptoms of abdominal distention and dissatisfaction with bowel movements. Pain thresholds and MI during distention were uncorrelated. Conclusions Pain sensitivity and colon motility are independent factors contributing to IBS symptoms. Treatment may need to address both and to be specific to predominant bowel habit.