Irritable bowel syndrome: A disease still searching for pathogenesis, diagnosis and therapy

Table 1 Factors potentially involved in the pathogenesis of irritable bowel syndrome

Altered intestinal motility

Food intolerance/allergy

Enteric infection/inflammation

Altered intestinal immunity

Altered gut microbiota

Genetics

Psychological distress and disorders; sexual abuse

Table 2 Most frequently reported comorbidities in irritable bowel syndrome patients

Functional dyspepsia and functional heartburn

Fibromyalgia

Chronic fatigue syndrome

Back pain

Multiple chemical sensitivity syndrome

Post-traumatic stress disorder

Psychological/psychiatric disorders

Sleep disturbances

Migraine and tension headaches

Table 3 Diseases and conditions considered in the differential diagnosis

Celiac disease and malabsorption

Lactose intolerance, fructose intolerance

Inflammatory bowel disease

Lymphocytic and collagenous colitis

Whipple's disease

Colonic cancer

Enteric infections

Metabolism disorders (e.g., thyroid, diabetes, etc.)

Food allergy and intolerance

Endometriosis

SIBO

Neuroendocrine tumors

Drugs

SIBO: Small intestinal bacterial overgrowth.

Table 4 Indication of pharmacological agents in individual irritable bowel syndrome symptoms

Constipation	Diarrhoea	Pain
Soluble fibre	Opioid agents	Antispasmodics
Osmotic Laxative	5-HT3 antagonists	Peppermint oil
5-HT4 agonists	Probiotics	Serotoninergic drugs
Secretagogues	Antibiotics	Antidepressants
Probiotics	Mesalazine	Herbal therapy
SSRI	Colestyramine	Acupuncture
	Tricyclic antidepressants

SSRI: Selective serotonin reuptake inhibitors.