This study estimated the total medical cost of care and described characteristics of patients with constipation in the United States. The 2001 National Ambulatory Medical Care Survey, National Hospital Ambulatory Medical Care Survey, and National Hospital Discharge Survey were used to provide national estimates. Patients diagnosed with constipation, or whose constipation was a reason for the visit, were identified. Medicare reimbursement rates based on recognized diagnostic and procedural codes were used to value each visit related to constipation. Constipation was a diagnosis or reason for seeking care in an estimated 5.7 million ambulatory visits and was the primary diagnosis or reason for 2.7 million of those visits. Of these visits, 1,838,493 were outpatient physician, 297,927 were outpatient hospital, and 555,432 were emergency department. Constipation was the primary diagnosis in 38,361 additional inpatient visits. Total cost was dollar 235 million per year, with 55% incurred from inpatient care and 23%, 16%, and 6% from ED, outpatient physician, and outpatient hospital settings, respectively. Constipation is treated primarily in ambulatory settings, but the costs of inpatient care exceed those of ambulatory care.