instruction: how many patients were diagnosed since 4 years ago with pleural effusion - right within 2 months after receiving laxatives - enema?
response: SELECT COUNT(DISTINCT t1.uniquepid) FROM (SELECT patient.uniquepid, treatment.treatmenttime FROM treatment JOIN patient ON treatment.patientunitstayid = patient.patientunitstayid WHERE treatment.treatmentname = 'laxatives - enema' AND DATETIME(treatment.treatmenttime) >= DATETIME(CURRENT_TIME(), '-4 year')) AS t1 JOIN (SELECT patient.uniquepid, diagnosis.diagnosistime FROM diagnosis JOIN patient ON diagnosis.patientunitstayid = patient.patientunitstayid WHERE diagnosis.diagnosisname = 'pleural effusion - right' AND DATETIME(diagnosis.diagnosistime) >= DATETIME(CURRENT_TIME(), '-4 year')) AS t2 WHERE t1.treatmenttime < t2.diagnosistime AND DATETIME(t2.diagnosistime) BETWEEN DATETIME(t1.treatmenttime) AND DATETIME(t1.treatmenttime, '+2 month')