New insights into irritable bowel syndrome: from pathophysiology to treatment

Abstract

Irritable bowel syndrome (IBS) is the most common reason to visit a gastroenterologist. IBS was believed to be a functional disease, but many possible pathophysiologic mechanisms can now explain the symptoms. IBS patients are classified into subtypes according to their predominant bowel habit, based on the Rome IV criteria. These include diarrhea-predominant and constipation-predominant IBS, as well as the mixed type, a combination of the two. Usually, IBS treatment is based on the predominant symptoms, with many options for each subtype. A new promising treatment option, fecal microbiota transplantation, seems to have beneficial effects on IBS. However, treating the pathophysiological causative agent responsible for the symptoms is an emerging approach. Therefore, before the appropriate therapeutic option is chosen for treating IBS, a clinical evaluation of its pathophysiology should be performed.

Irritable bowel syndrome - risk factors, pathogenesis and treatment options

“…Some clusters of fecal metabolites or microorganisms were significantly correlated with the severity of IBS symptoms, such as the frequency of abdominal pain/discomfort and the number of bowel movements [42]. Central nervous system signals are transmitted to the gut by neuroendocrine neurotransmitters (serotonin, corticotropin-releasing hormone, cholecystokinin, and somatostatin) which are produced in the gut by immune and enterochromaffin cells to alter microbiota behavior [43]. The gut microbiota has provided support to the concept that a disturbed intestinal ecology could promote development and maintenance of symptoms in irritable bowel syndrome [44].…”

The Diagnosis Performance of the TCM Syndromes of Irritable Bowel Syndrome by Gastroenterologists Based on Modified Simple Criteria Compared to TCM Practitioners: A Prospective, Multicenter Preliminary Study

“…It is associated with heavy costs to patients and society [ 3 ]. The pathophysiology of IBS involves multiple factors, such as brain-gut disorder, gastrointestinal infection, visceral hypersensitivity, increased intestinal permeability, psychiatric and psychological conditions such as anxiety and depression, abnormal gastrointestinal motility, altered gut microbiota, immune dysfunction, and host genetic susceptibility [ 4 , 5 ].…”

Microbiome and Metabolome of Patients with Slow Transit Constipation: Unity in Diversity?

“…Though these microorganisms are mostly bacteria, the microbiota also include viruses, fungi, and protozoa living together and interacting with each other and with the host. A good example of this interaction is termed the gut-brain axis, although the composition of gut microbiota is associated with alterations of the paracellular permeability of the GI tract epithelium [1].…”

“…At the moment, the most supported theory is that decreased microbial richness and diversity correlate with disease [5]. Although there are very few current causal studies, the presence of Bifidobacteria together with Lactobacillus and other related species is considered as beneficial bacteria [1]. Also, Bifidobacteria are one of the main species included in most of the available therapeutic probiotic bacteria preparations [4].…”

“…STC usually is a chronic disease that affects 15-30% of patients with constipation. Even though the pathophysiological mechanisms are not clearly understood, it is believed that the disease is mostly due to pathologic alterations of the enteric and the autonomic nervous systems in addition to dysregulation of the neuroendocrine system [8] as is hypothesized with other functional gastrointestinal disorders [1]. Therefore, microbiota-related therapies might worth trying in patients with STC given the caveats that there is no guarantee that orally introduced bacteria will populate the hindgut.…”