Irritable bowel syndrome: the most effective dietary supplements

Irritable bowel syndrome (IBS), also called functional bowel disorder, is a common functional digestive disorder affecting about 15 to 20% of the world population, with increased prevalence in women. Characterized by recurrent abdominal pain associated with altered bowel habits (constipation, diarrhea, or alternating between the two), IBS is distinguished by the absence of visible organic abnormalities on clinical and laboratory examinations.

Physiopathology

The pathophysiology of IBS remains multifactorial and incompletely understood. It includes: • Dysfunction of intestinal motilityIn IBS, intestinal contractions are often irregular: either too fast in diarrheal forms, or too slow in constipated forms. These motor abnormalities disrupt transit, explaining the symptoms specific to each subtype. The colonic response to food is also altered, exacerbating postprandial pain. • Visceral hypersensitivityAn increased sensitivity of intestinal nerves amplifies the perception of pain in patients with IBS, even in the absence of inflammation. This hypersensitivity, due to hyperactivity of serotonergic and cholinergic receptors, is often linked to increased permeability of the intestinal mucosa. • Imbalance of the intestinal microbiota and inflammationThe gut microbiota plays a key role in IBS. Qualitative and quantitative alterations (dysbiosis) can promote increased gas production and digestive disturbances. These changes, often triggered by infections or antibiotics, also influence the immune system through the release of pro-inflammatory cytokines. • Involvement of the central nervous systemThe gut-brain axis is central in IBS. Psychological stress disrupts neuro-gastroenteric signaling, leading to increased secretion of serotonin, a neurotransmitter involved in intestinal motility and mood regulation. A decrease in serotonin reuptake transporters has been observed in some patients, promoting motor and sensory disturbances.

Trigger and risk factors

IBS often results from the interaction of multiple factors: • Psychological stress and emotional history : Chronic stress disrupts the gut-brain axis and amplifies symptoms. • Gastrointestinal infections : Acute gastroenteritis can durably disturb intestinal motility and the microbiota. • Unbalanced diet : Meals high in fermentable sugars (FODMAPs) or fats worsen symptoms. • Repeated antibiotic use : This can lead to dysbiosis, weakening the intestinal barrier.

Clinical signs

The diagnostic criteria for IBS, as defined by the Rome II and III classifications, help identify the condition in the absence of biological or structural abnormalities. • Abdominal pain : Spasmodic or diffuse, it occurs during the daytime and is often relieved by defecation or the passage of gas. • Bowel transit disorders : Constipation, diarrhea, or alternation between the two, with stools sometimes mucous. • Bloating and flatulence : Perceived as abdominal distension, often worsened after meals. • Associated extra-digestive symptoms: Patients may also present with headaches, chronic pelvic pain, back pain, or sleep disturbances and chronic fatigue. These manifestations reflect systemic involvement.

Diagnosis

The diagnosis of IBS is based on the Rome III criteria and on excluding other digestive pathologies (inflammatory bowel diseases, celiac disease, lactose intolerance). Additional tests include: • Laboratory tests : To rule out nutritional deficiencies or inflammatory syndromes. • Colonoscopy : Indicated in the presence of alarm signs (weight loss, or recent symptoms in patients over 50 years of age).

Management

Treatment of IBS is individualized and aims to improve symptoms while taking psychological and environmental factors into account. • Dietary changes : Avoiding trigger foods, following a low-FODMAP diet, or adding fiber may be recommended. • Medications : Antispasmodics for pain, laxatives for constipation, or antidiarrheals. Low-dose antidepressants may be prescribed in cases of severe pain or associated anxiety. • Behavioral therapies : Stress management techniques, such as cognitive-behavioral therapy or hypnotherapy, show promising results. • Probiotics : Although evidence is limited, some probiotics may improve symptoms. The prognosis of IBS is generally favorable. Although it is a chronic condition, symptoms can fluctuate and respond to appropriate treatments. However, quality of life can be significantly impaired, requiring psychological support in severe cases.