The history of
botulinum toxin is fascinating. First recognized as the cause of
botulism nearly 200 years ago, it was originally feared as a deadly
poison. Over the last 30 years, however,
botulinum toxin has been transformed into a readily available medication used to treat a variety of medical disorders. Interest in the use of
botulinum toxin has been particularly strong for patients with
spastic smooth muscle disorders of the gastrointestinal tract. Patients with
achalasia,
diffuse esophageal spasm,
gastroparesis,
sphincter of Oddi dysfunction, and anal fissures have all been treated with
botulinum toxin injections, often with impressive results. However, not all patients respond to
botulinum toxin therapy, and large randomized controlled trials are lacking for many conditions commonly treated with
botulinum toxin. This paper reviews the history, microbiology, and pharmacology of
botulinum toxin, discusses its mechanism of action, and then presents recent evidence from the literature regarding the use of
botulinum toxin for the treatment of a variety of gastrointestinal tract disorders.