We aimed to evaluate the efficacy of intracutaneous sterile water injection (ISWI) to relieve the pain of acute renal colic compared with diclofenac and placebo.

The study included 150 patients presented to the Emergency Department with renal colic randomized into 3 groups: control group received intracutaneous injections of 0.5 cm³ isotonic saline in the flank, group A received intracutaneous injections of 0.5 cm³ ISWI in the flank, and group B received an intramuscular injection of 75 mg Diclofenac in the gluteal region. The severity of the pain was assessed by a visual analogue scale system at baseline and 30, 45 min, and 60 min after injections. Subjects with inadequate pain relief at 1 h received rescue analgesia.

The mean baseline pain score was 9.6 ± 0.61 in the ISWI group, 9.72 ± 0.64 in the diclofenac group and 9.26 ± 0.89 in the control group.

The mean pain score at 30 min of the control group was reduced to 6.9 ± 1.56. This mean at 30 min after ISWI and diclofenac injections were reduced to 1.98 ± 1.41 and 1.88 ± 1.19 respectively.

The mean of pain sore of the ISWI and diclofenac group at 45 and 60 min was constant.

Rescue analgesics at 1 h were required by 47 patients receiving the saline injection and by 4 patients and by 7 patients receiving ISWI and diclofenac injection respectively.

ISWI and diclofenac were equally effective for the pain relief of acute renal colic.