BACKGROUND

Postoperative ileus, driven by the cholinergic anti-inflammatory pathway, is the most common complication in patients undergoing colorectal surgery. By inhibiting acetylcholinesterase, pyridostigmine can potentially modulate the cholinergic anti-inflammatory pathway and accelerate gastrointestinal recovery. This study aimed to assess the efficacy of pyridostigmine in improving gastrointestinal recovery after colorectal surgery.

METHODS

This double-blinded RCT enrolled adult patients undergoing elective colorectal surgery at two hospitals in South Australia. Patients were randomized to 60 mg oral pyridostigmine or placebo twice daily starting 6 h after surgery until the first passage of stool. The primary outcome was GI-2, a validated composite measure of time to first stool and tolerance of oral diet. Secondary outcomes included incidence of postoperative ileus (defined as GI-2 greater than 4 days), duration of hospital stay, and 30-day complications, evaluated by intention-to-treat univariate analysis.

RESULTS

Of 130 patients recruited (mean(s.d.) age 58.4(16.4) years; 73 men, 56%), 65 were allocated to each arm. The median GI-2 was 1 day shorter with pyridostigmine compared with placebo (2 (i.q.r. 1-3) versus 3 (2-4) days; P = 0.015). However, there were no significant differences in postoperative ileus (17.2 versus 21.5%; P = 0.532) or duration of hospital stay (median 5 (i.q.r. 4-8.75) versus 5 (4-7.5) days; P = 0.921). Similarly, there were no significant differences in overall complications, anastomotic leak, cardiac complications, or patient-reported side effects.

CONCLUSION

Pyridostigmine resulted in a quicker return of GI-2 and was well tolerated. Larger multicentre studies are required to determine the optimal dosing and evaluate the impact of pyridostigmine in different surgical settings. Registration number: ACTRN12621000530820 (https://anzctr.org.au).