Comparison 1. Local anaesthetic versus placebo.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Pain at rest: day 1 (10‐point numerical rating scale or equivalent)	5	511	Mean Difference (IV, Random, 95% CI)	‐0.59 [‐1.12, ‐0.07]
2 Pain at rest: day 2 (10‐point numerical rating scale or equivalent)	5	511	Mean Difference (IV, Random, 95% CI)	‐0.30 [‐0.68, 0.08]
3 Pain at rest: day 3 (10‐point numerical rating scale or equivalent)	3	422	Mean Difference (IV, Random, 95% CI)	‐0.24 [‐0.58, 0.10]
4 Pain on movement: day 1 (10‐point numerical rating scale or equivalent)	3	407	Mean Difference (IV, Random, 95% CI)	‐1.13 [‐2.26, ‐0.01]
5 Pain on movement: day 2 (10‐point numerical rating scale or equivalent)	3	407	Mean Difference (IV, Random, 95% CI)	‐0.86 [‐1.79, 0.08]
6 Pain on movement: day 3 (10‐point numerical rating scale or equivalent)	2	352	Mean Difference (IV, Random, 95% CI)	‐0.57 [‐1.03, ‐0.12]
7 Opioid consumption via patient controlled analgesia: day 1 (mg morphine equivalent)	6	528	Mean Difference (IV, Random, 95% CI)	‐11.98 [‐19.80, ‐4.17]
8 Opioid consumption via patient controlled analgesia: day 2 (mg morphine equivalent)	6	528	Mean Difference (IV, Random, 95% CI)	‐9.64 [‐15.77, ‐3.52]
9 Opioid consumption via patient controlled analgesia: day 3 (mg morphine equivalent)	4	451	Mean Difference (IV, Random, 95% CI)	‐4.93 [‐10.95, 1.09]
10 Opioid consumption via patient controlled analgesia: day 4 (mg morphine equivalent)	2	71	Mean Difference (IV, Random, 95% CI)	‐2.27 [‐6.85, 2.31]
11 Nausea or vomiting	6	541	Risk Ratio (M‐H, Random, 95% CI)	0.90 [0.71, 1.14]
12 Ileus	3	155	Risk Ratio (M‐H, Random, 95% CI)	0.49 [0.14, 1.77]
13 Pruritus	3	395	Risk Ratio (M‐H, Random, 95% CI)	0.83 [0.38, 1.82]
14 Respiratory depression	2	125	Risk Ratio (M‐H, Random, 95% CI)	0.21 [0.02, 1.77]
15 Time to first bowel movement (days)	4	197	Mean Difference (IV, Random, 95% CI)	‐0.67 [‐1.17, ‐0.17]
16 Time to ambulation (days)	3	159	Mean Difference (IV, Random, 95% CI)	‐0.53 [‐1.28, 0.22]
17 Length of hospital stay (days)	4	456	Mean Difference (IV, Random, 95% CI)	‐1.17 [‐2.01, ‐0.33]
18 Any serious postoperative adverse event (composite outcome)	6	541	Risk Ratio (M‐H, Random, 95% CI)	1.04 [0.68, 1.58]
19 Pneumonia	3	435	Risk Ratio (M‐H, Random, 95% CI)	1.15 [0.47, 2.82]
20 Laparotomy wound breakdown	2	340	Risk Ratio (M‐H, Random, 95% CI)	0.32 [0.09, 1.12]
21 Laparotomy wound infection	5	499	Risk Ratio (M‐H, Random, 95% CI)	1.18 [0.58, 2.37]
22 Local anaesthetic systemic toxicity	2	72	Risk Ratio (M‐H, Random, 95% CI)	0.0 [0.0, 0.0]