This is a prospective, randomized, single-blind study. Patients included in the study after successful treatment of the acute attack were randomized upon discharge from the Emergency Department into three groups: oral paracetamol-tramadol group, oral paracetamol-caffeine group and oral placebo group.

This is a prospective, randomized, single-blind study. Patients included in the study after successful treatment of the acute attack were randomized upon discharge from the Emergency Department into three groups: oral paracetamol-tramadol group, oral paracetamol-caffeine group and oral placebo group.

Different parameters are collected on a standard form prepared for all cases of renal colic included in our study. This sheet essentially contains:

Temperature, systolic and diastolic blood pressure, heart rate, pain intensity assessed by VAS, abdominal tenderness as well as the existence of Giardano signs.

Additional examinations were not systematically carried out for all patients: AUSP, ECBU, renal ultrasound, creatinemia and blood sugar. Their realization depended on the clinical context.

The use of imaging was done following the indications specified in the text of the consensus of the French Society of Emergency Medicine (updated in 2008)

Inclusion Criteria:

• -Age > 18 years old.
• Consent to participate in the study.
• Pain in the flank/lumbar fossa of sudden onset with urine strips and/or imaging corresponding to the diagnosis of renal colic.
• Pain score at discharge < 30 (visual analog scale - VAS or verbal numerical scale - VAS from 0 to 100).

Exclusion Criteria:

• -Inability to appreciate pain according to the VAS.
• Pregnant or breastfeeding woman.
• Renal insufficiency with creatinine clearance < 60 ml/min.