Study of Effect of Tegaserod on Small and Large Bowel Transit by Scintigraphic Method

Inclusion Criteria: * History of functional constipation as proposed by the Rome II Criteria and the usual frequency of spontaneous bowel motion must be equal or less than 2 times /week. * An endoscopic/radiologic bowel evaluation (colonoscopic examination and/or a sigmoidoscopy + barium enema) is required in patients older than 40 years. This evaluation must have been performed within the past 5 years. In addition, there should not be history or evidence of weight loss, anemia or rectal bleeding since the evaluation was performed. Note: For patients who require these procedures, these tests should be performed after the patient has signed informed consent and at least 7 days PRIOR to the start of the diaries (washout period). The 7-day window is to allow the patient to recuperate prior to collecting baseline data. A copy of the report should be placed in the patient source document. * Patients who are able to communicate well with the investigator and to comply with the requirements for the entire study, including the withdrawal period. * Patients who provide written informed consent before participating in the study after being given a full description of the study. Exclusion Criteria: * Medications known to affect gastrointestinal transit before 1 week of the treatment phase of the study. * With clinical evidence (including physical exam, vital signs, ECG, laboratory tests) of significant cardiovascular, respiratory, renal, hepatic, gastrointestinal, hematology, endocrine or metabolic disorders, neurologic disease, or of any disease that may interfere with the patient successfully completing the study. * Existence of surgical or medical conditions which interfere with the absorption, distribution, metabolism and excretion of the study medication. * With hypo or hyper thyroidism (clinically significant abnormal TSH level at screening). * With symptoms of a significant clinical illness in the two weeks preceding baseline. * With other relevant intercurrent medical condition that may interfere with the objectives of the study. * Women who are pregnant or breast-feeding. * With evidence or history of drug or alcohol abuse within the past 12 months. * Who received another investigational drug within the 30 days prior to entry in the study.