Role of serotonin in the pathophysiology of the irritable bowel syndrome

Br J Pharmacol. 2004 Apr;141(8):1285-93. doi: 10.1038/sj.bjp.0705762.


The irritable bowel syndrome (IBS) is a complex disorder that is associated with altered gastrointestinal motility, secretion, and sensation. Serotonin (5-HT) is an important neurotransmitter and paracrine signalling molecule in the gastrointestinal tract. 5-HT release from enterochromaffin (EC) cells initiates peristaltic, secretory, vasodilatory, vagal and nociceptive reflexes. The enteric nervous system (ENS) comprises a semiautonomous effector system that is connected to the central autonomic network. Parasympathetic and sympathetic nerves modulate the ENS via afferent and efferent communications. Ongoing, bidirectional brain-gut interactions involving 5-HT pathways occur that significantly influence the effector systems. Altered 5-HT signalling may lead to both intestinal and extraintestinal symptoms in IBS. 5-HT directly and indirectly affects intestinal motor and secretory function and abnormalities may lead to either constipation or diarrhea. 5-HT modulates sensation and perception of visceral stimulation at peripheral and central sites. Therapeutic agents targeting altered 5-HT signalling may provide new, effective treatments for patients with IBS.

Publication types

  • Review

MeSH terms

  • Animals
  • Gastrointestinal Motility / drug effects
  • Gastrointestinal Motility / physiology
  • Humans
  • Irritable Bowel Syndrome / drug therapy
  • Irritable Bowel Syndrome / metabolism*
  • Receptors, Serotonin / physiology
  • Serotonin / physiology*
  • Serotonin Agents / pharmacology
  • Serotonin Agents / therapeutic use


  • Receptors, Serotonin
  • Serotonin Agents
  • Serotonin