According to Mayo Clinic gastroenterologist Michael Picco, spastic colon is another name for what doctors call irritable bowel syndrome. The term "spastic colon" arose from motility studies that showed that the colons of people with irritable bowel syndrome contract more often than normal. Depending on what set of muscles contract---the colon has two---the result may be either constipation or diarrhea. Antispasmodics help treat excessive muscle contractions due to spastic colon.
Mechanism of Action
Antispasmodics blunt cells' responses to the substance acetylcholine, which is released by nerve terminals in the bowel and other parts of the body. Acetylcholine triggers the reflex contractions that occur in the intestine when food arrives in the stomach.
Administration
Patients typically take antispasmodics by mouth, three times per day, 30 to 60 minutes before eating. The dose depends on the brand prescribed; almost all of the drugs belong to the family of drugs known as natural belladonna alkaloids or another family known as synthetic anticholinergics.
Side Effects
Side effects of antispasmodics include dry mouth, urinary hesitation, urinary retention, blurred vision and drowsiness. Severe side effects and side effects that last longer than a few weeks are a common reason for discontinuing antispasmodics.
Warnings
Older people and people with liver or kidney problems do not metabolize antispasmodics efficiently, so they often experience more severe side effects that last longer. All people who take antispasmodics should avoid hot dry weather because antispasmodics impair the ability to dissipate heat through sweating, increasing the risk of heatstroke and hyperthermia.
Effectiveness
A 2005 review published by the prestigious "Cochrane Database of Systematic Reviews" evaluated 11 studies including a total of 1,260 patients who received antispasmodics for irritable bowel syndrome. According to the authors, antispasmodics significantly improved abdominal pain and patients' overall assessment of their symptoms, although they did not reduce the incidence of constipation or diarrhea.
References
- MayoClinic.com: What is spastic colon?
- Irritable Bowel Syndrome (Chapter); C. Owyang; In: "Harrison's Principles of Internal Medicine, 19th edition;" A.S. Fauci et al. (eds); 2008
- "Cochrane Database of Systematic Reviews;" Bulking Agents, Antispasmodic and Antidepressant Medication for the Treatment of Irritable Bowel Syndrome; A.O. Quartero et al.; April 2005
- MayoClinic.com: Irritable bowel syndrome
