Timing - both of the following:
(1) symptoms last at least 12 weeks (not necessarily consecutive)
(2) in the past 12 months
Diagnostic features:
(1) abdominal discomfort and pain, AND
(2) onset associated with either a change in frequency and/or form (appearance) of stool
Supportive symptoms, general:
(1) feeling of incomplete bowel movement
(2) passing mucus (whitish material) during a bowel movement
(3) feeling of abdominal fullness, bloating or swelling
Supportive symptoms, diarrhea predominant - one or more of the following:
(1) more than 3 bowel movements a day
(2) loose (mushy) or watery stools
(3) urgency (having to rush to have a bowel movement)
Supportive symptoms, constipation predominant - one or more of the following:
(1) fewer than 3 bowel movements a week
(2) hard or lumpy stools
(3) straining during a bowel movement
NOTES:
(1) This is a diagnosis of exclusion.
(2) It is important to exclude certain foods as the cause for changes. For example, a person with lactose intolerance who only intermittently drank milk might meet these criteria.
(3) The presence of fever, rectal bleeding and weight loss should prompt an investigation for another disorder.
(4) Young women with IBS may notice a worsening of symptoms during menses and they may be evaluated for a gynecologic problem.
(5) The workup for irritable bowel syndrome should include exclusion of adult celiac disease, with testing for antigliadin and antiendomysial antibodies.
