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Home Offer Syndromes Irritable bowel syndrome (IBS)

Irritable bowel syndrome is a disease whose symptoms include abdominal pain and stool changes. The disease is diagnosed by exclusion.

Definition

Irritable bowel syndrome is present when all three of the following points are met:

  • The presence of chronic symptoms (e.g. abdominal pain, bloating) that have persisted for more than 3 months, which are referred to the bowel by the affected person and the treating physician and are usually accompanied by changes in bowel movements.
  • The patient seeks help because of the symptoms and/or is so worried that their quality of life is significantly impaired.
  • The symptoms present cannot be explained by another illness.

Severity of the disease

There are various validated severity scores, the most commonly used of which is the IBS severity scoring system (IBS-SSS). This score reflects the physician's view and includes the parameters pain, distension, bowel dysfunction and quality of life.

Epidemiology

The prevalence of irritable bowel syndrome is between 2.5 and 25%, depending on the diagnostic criteria used. This makes irritable bowel syndrome the most common gastrointestinal disorder after dyspepsia. The disorder occurs more frequently in women than in men (2:1). It can also occur in all age groups. The prevalence is lower in higher income groups.

Causes

The etiology has not been conclusively clarified. Irritable bowel symptoms can be triggered by an enteric infection. A genetic predisposition to irritable bowel syndrome has also been shown. However, intrafamilial factors, coping strategies or environmental factors could also play a role here. Stress appears to be able to trigger or at least exacerbate symptoms of irritable bowel syndrome.

Pathogenesis

The pathogenesis of irritable bowel syndrome has also not been conclusively clarified. It is assumed that irritable bowel syndrome is based on disorders of the intestinal barrier, motility, secretion and/or visceral sensitivity.

Increased permeability caused by reduced mRNA expression of the tight junction protein zonula-occludens-1 has been shown in colon biopsies of affected patients. This is associated with visceral hypersensitivity. It has also been shown that the colonic transit time is altered in irritable bowel patients. Intestinal motility is also increased in those affected. The microinflammatory/neuroimmunological processes in the intestinal mucosa are associated with an increase in immune cells and/or EC cells. In addition, there is an increased innervation of the mucosa and an altered sympathetic/parasympathetic activation in those affected. Irritable bowel syndrome is also associated with altered intestinal flora.

Learned illness behavior also plays a role in the development of irritable bowel syndrome. A clear causal relationship between the presence of psychological stress and irritable bowel syndrome has not yet been demonstrated. However, stress could have a negative influence on the course of irritable bowel syndrome. In animal models, altered gastrointestinal functions caused by stress have been demonstrated, which could play a role in the pathogenesis of the disease.

Symptoms

Patients can suffer from a variety of symptoms. As a rule, the main symptoms are diarrhea, pain, constipation, flatulence or distension. Often either diarrhea or constipation dominate in a patient.

Patients complain of pressure and a feeling of fullness after meals. There is also a pathological urge to defecate and a feeling of incomplete bowel evacuation. The feeling of abdominal pressure and fullness usually improves after defecation.

Warning signs that speak against irritable bowel syndrome are, for example, the presence of nocturnal diarrhea, fever, blood in the stool and weight loss.

Diagnostics

The diagnosis begins with the patient's medical history. In particular, the typical and compatible constellation of symptoms must be evaluated.

Differential diagnoses

The next step is to rule out possible differential diagnoses. These include, for example

Particular attention must be paid to the presence of alarm symptoms. In up to 5% of patients who are initially clinically diagnosed with irritable bowel syndrome, an organic disease turns out to be the cause of the symptoms in the short to medium term. For example, the incidence of colorectal carcinoma in irritable bowel syndrome patients was 1% and was significantly higher than in the normal population. In ovarian cancer patients, too, typical irritable bowel symptoms are usually the only symptom present more than 6 months before diagnosis.

Basic diagnostics

The medical history should be followed by a basic diagnosis. This should include a physical examination including a rectal examination.

A basic laboratory diagnosis should also be carried out. This should include at least a blood count, erythrocyte sedimentation rate, C-reactive protein and urine status. It should be evaluated individually whether serum electrolytes, kidney retention values, liver and pancreatic enzymes, TSH, blood sugar/HbA1c, stool microbiology, celiac disease antibodies (transglutaminase antibodies) and calprotectin A/lactoferrin in the stool should also be examined.

An abdominal ultrasound examination should also be performed. In women, a gynecological cause of the symptoms should be ruled out.

In order to confirm the diagnosis of irritable bowel syndrome, the guideline recommends performing an ileocolonoscopy in adults to rule out relevant differential diagnoses such as colorectal carcinoma.

Especially in the presence of diarrhea as a major symptom, the guideline recommends a detailed diagnostic clarification including pathogen diagnostics in the stool as well as endoscopic (including staged biopsies) and functional diagnostic examinations. Patients with chronic diarrhea usually have an identifiable and treatable disorder.

In summary, irritable bowel syndrome is currently diagnosed if the above examinations are unremarkable (physical examination, laboratory including stool examination, sonography, possibly ileocolonoscopy).

Therapy

General principles of therapy

Patients should be given an individualized disease model and congruent treatment concept. Possible individual trigger factors should be taken into account. Dietary and lifestyle recommendations should take the individual trigger factors into account.

Diet: There are currently no standardized dietary recommendations. Individual dietary recommendations should be based on the respective symptoms. Nutritional advice can be helpful for those affected. Selected probiotics can be used in the treatment of irritable bowel syndrome according to the guidelines. In addition, soluble fibers such as psyllium/plantago and ispaghula can be used in therapy. In order to increase the positive effect, care should be taken to drink sufficient amounts. Dietary fibers can be used in patients with predominantly obstipative symptoms, but also in patients with predominantly diarrhea or pain as symptoms.

Due to the heterogeneity of the clinical picture, there is no standard therapy. An attempt at drug therapy without adequate improvement of the symptoms should be discontinued after 3 months at the latest and replaced by another agent if necessary. Due to the benign nature of irritable bowel syndrome, a careful individual risk-benefit assessment must always be carried out when using a therapy.

Inclusion of the psyche

Psychological influencing factors (e.g. the presence of occupational or family stress factors), anxiety, depression and the tendency to somatization should be recorded in order to positively influence the success of treatment.

In individual cases, complementary therapy methods such as acupuncture or yoga can be used in the treatment of irritable bowel syndrome in accordance with the guideline. If necessary, the guideline recommends psychological/psychosomatic care for those affected. Psychotherapeutic methods such as cognitive behavioral therapy, psychodynamic therapy or gut-related hypnosis should be integrated into the treatment concept for irritable bowel syndrome.

If psychological comorbidities (anxiety disorder, depression) are present, the guideline gives an "optional" recommendation for the prescription of antidepressants. It should be noted here that patients with predominantly obstipative symptoms should not receive tricyclic antidepressants. Serotonin reuptake inhibitors (SSRIs), for example, can be used for them.

Pain treatment

Neither peripheral analgesics (acetylsalicylic acid, paracetamol, NSAIDs, metamizole) nor opiods and opiod agonists should be used to treat pain.

For pain therapy, the guideline recommends spasmolytics, for example. Soluble fiber and probiotics can also have a pain-relieving effect. Tricyclic antidepressants and SSRIs can also be used for pain therapy. Phytotherapeutics can also be used for pain therapy.

Treatment of diarrhea

The guideline advocates the use of loperamide in the treatment of diarrhea in irritable bowel syndrome patients. Dietary fiber and probiotics can also help here. According to the guideline, treatment with colestyramine can be carried out. Phytotherapeutics and spasmolytics can also help patients with stool irregularities.

Treatment of constipation and flatulence

In the treatment of constipation and flatulence in irritable bowel syndrome, dietary fibres such as psyllium husks should be tried. Osmotic laxatives, for example of the macrogel type, can also be used.

An attempt at therapy with prucalopride can be tried in refractory cases. Probiotics can also be used. The phytopharmaceutical STW-5 has been shown to be effective in the treatment of irritable bowel syndrome.

Spasmolytics can also be used in therapy. In addition, SSRIs can be tried in the case of predominant pain and/or psychological comorbidity. Flatulence/abdominal distension/meteorism and flatulence can be improved with probiotics. Rifaximin can also be tried in cases of refractory symptoms. Phytopharmaceuticals can also have a positive effect on the symptoms.

Prognosis

Irritable bowel syndrome can regress spontaneously. However, it usually takes a chronic course. The disease shows no increased co-prevalence with other serious gastrointestinal diseases. There is an association with somatoform and mental disorders, e.g. depression, fatigue syndrome, fibromyalgia syndrome. Irritable bowel syndrome patients have a normal life expectancy. However, patients' quality of life can be severely impaired.

Prophylaxis

There is currently no prophylaxis that can prevent the occurrence of irritable bowel syndrome. A healthy, balanced diet, exercise and stress reduction/relaxation can help to maintain intestinal health.