Key Points
Î Irritable bowel syndrome (IBS) is the most common diagnosis
in clinical gastroenterology. It is estimated that approximately
10%–15% of the general adult population is affected.
Î For this review, the important role of nonpharmacological
therapies, including dietary and lifestyle modification, was not
considered.
Î IBS is a chronic functional gastrointestinal disorder
characterized by abdominal pain and/or discomfort associated
with altered defecation. Other common symptoms include
bloating, straining, rectal urgency, and the sensation of
incomplete evacuation.
Î The current Rome III criteria for IBS require the presence of
recurrent abdominal pain and/or discomfort at least 3 days/
month in the past 3 months that is associated with 2 or more of
the following: improvement with defecation, onset associated
with a change in stool frequency or in form (appearance) of
stool. Symptoms have to be present for at least 6 months.
Î Further subclassification is based on the predominant stool
consistency: IBS with constipation (IBS-C), IBS with diarrhea
(IBS-D), IBS with mixed pattern (IBS-M), and unsubtyped IBS.
Î Current pharmacological treatments are generally aimed at
improving one or more of the predominant symptoms, such
as abdominal pain, constipation, or diarrhea. Commonly
used pharmacological therapies for IBS include linaclotide,
lubiprostone, polyethylene glycol (PEG) laxative, rifaximin,
alosetron, loperamide, tricyclic antidepressants (TCAs),
selective serotonin reuptake inhibitors (SSRIs), and
antispasmodics.
AGA Institute Guidelines on the Pharmacological Management of Irritable Bowel Syndrome