This study will look at how the body interacts with citalopram in adult participants with short bowel syndrome. While information on depression in patients with short bowel syndrome is sparse, the investigators' experience is that these patients have a high incidence of depression and should benefit from a drug intervention.

This prospective study will determine the pharmacokinetic parameters of citalopram in 12 adult patients with short bowel syndrome. While data on the prevalence of depression in patients with short bowel syndrome is sparse, the investigators' experience is that these patients have a high incidence of depression and should benefit from a psychopharmacological intervention.

Inclusion Criteria:

• Subjects must be between the ages 19-65 years.
• Subjects must have less than 200cm of functional small intestine.
• Subjects must be at least one month post bowel resection.

Exclusion Criteria:

• Subjects less than 19 years or more than 65 years of age.
• Pregnant or breastfeeding women.
• Known hypersensitivity to citalopram or other SSRIs.
• Diagnosis of depression using MINI (Mini International Neuropsychiatric Interview).
• Ongoing antidepressant therapy.
• Evidence of cirrhosis (Child-Pugh stages B or C) or evidence of significant liver impairment defined as liver enzymes elevations greater that 2.5 times the upper limit of normal.
• Suicidal ideation.
• Bipolar disorder.
• Mania.
• Known history of seizures.
• Evidence of hyponatremia.