Recent literature has demonstrated that the group of IBS sufferers who experience mixed bowel habits may be more similar to IBS-C patients than IBS-D patients. This study will evaluate the efficacy and safety of tegaserod 6 mg b.i.d. in women with IBS and mixed bowel habits, excluding those with predominant diarrhea.

Inclusion Criteria:

• women, outpatients, 18-65 years of age with IBS-C or IBS with mixed bowel habits
• In the 12 months preceding study entry, they had to have at least 12 weeks (not necessarily consecutive) of abdominal discomfort/pain with 2 out of 3 features: 1) relieved with defecation; 2) onset associated with a change in stool frequency; 3) onset associated with a change in form (appearance) of stool.
• Had to fulfill the following criteria (IBS questionnaire) during the last 3 months prior to study entry: abdominal discomfort or pain present during at least 3 weeks in the last 3 months, and at least two of the following: abdominal discomfort or pain gets better or stops after a bowel movement; change in bowel movement frequency when the abdominal discomfort or pain starts; change in bowel movement consistency when the abdominal discomfort or pain starts

Exclusion Criteria:

• IBS-D
• not reporting any constipation and diarrhea criteria
• evidence of structural abnormality of the gastrointestinal tract or diseases/conditions that affect bowel transit
• history of bowel obstruction, symptomatic gallbladder disease, suspected sphincter of Oddi dysfunction, or abdominal adhesions
• evidence of cathartic colon or history of laxative abuse

Other protocol-defined inclusion/exclusion criteria may apply.