instruction: give me the number of patients who had open and other sigmoidectomy and had psychiatric facility-partial hospitalization discharge.
response: SELECT COUNT(DISTINCT demographic.subject_id) FROM demographic INNER JOIN procedures ON demographic.hadm_id = procedures.hadm_id WHERE demographic.discharge_location = "DISCH-TRAN TO PSYCH HOSP" AND procedures.short_title = "Open sigmoidectomy NEC"