Incisional Hernia Repair After Bariatric Surgery
A bulge at a surgical scar or keyhole port after weight-loss surgery is a hernia, far more common after open operations, and is usually repaired with mesh once weight has stabilised.
Plain English
Patient-Friendly Explanation
An incisional hernia is a gap in the muscle wall at the site of an old operation scar or keyhole port, with fat or bowel pushing through it. Bariatric operations carry a higher risk than most abdominal surgery because the patients are heavy and, frequently, because wound infection and coughing strain the repair. The difference between techniques is large: after a keyhole operation a hernia appears in only a small percentage of patients, while after the older open operations roughly one in five patients develops one. Most show up as a soft lump that becomes more obvious when standing, coughing or lifting, sometimes with a dull ache. The serious risk is when bowel becomes trapped and strangulated, which causes severe pain, vomiting and a hard tender lump and needs emergency attention. Repair of a significant hernia means surgery, generally with a mesh to reinforce the abdominal wall, and it is timed once weight has plateaued because recurrence is more likely while someone is still heavy. Hernias found during a weight loss programme should be reviewed rather than ignored, even when they are not painful.
Medical
Clinical Definition
Incisional hernia after bariatric surgery is common and technique-dependent. In a series of 444 patients who had open Roux-en-Y gastric bypass, the incidence was 18.7% at a mean follow-up of two years, and post-operative wound problems requiring local care were the dominant predictor (33.8% of those patients developed a hernia, p=0.007), with pre-existing asthma also significant (34.4%, p=0.005); a separate open gastric bypass cohort reported 20% (198/968) against 4% (7/171) in non-obese colectomy or ileal pouch-anal anastomosis controls (p<0.001), the authors concluding that severe obesity is a greater risk factor for hernia and for recurrence than chronic corticosteroid use. A meta-analysis of randomised trials comparing laparoscopic with open bariatric surgery found a relative risk of 0.11 (95% CI 0.03-0.35) for incisional hernia and 0.21 (0.07-0.65) for wound infection with the laparoscopic approach, with no difference in anastomotic leak, reoperation or mortality. Trocar-site hernia after laparoscopic surgery is less common but real: 1.6% (10 of 624 patients) in one series at a mean of 15 months, and 3.8% of individual ports in a systematic ultrasound study, with almost all midline. Repair is by mesh hernioplasty - in an early open series prefascial polypropylene mesh gave 4% recurrence at about 20 months but 35% complications, predominantly minor wound infection, seroma and haematoma - and current practice favours laparoscopic or robotic mesh repair in patients with obesity, performed after weight stabilisation because recurrence risk tracks with residual adiposity and raised intra-abdominal pressure. Emergency presentation with strangulation or obstruction requires urgent operative management, and a rapidly expanding or painful hernia after bariatric surgery should be assessed the same day.
Key Insight
Why It Matters
A new bulge or dragging ache under a scar is not cosmetic housekeeping - if it becomes hard, painful and accompanied by vomiting, bowel may be trapped.
Sources
Reviewed against standard medical references.
Medically reviewed by
Family Physician & Registered Acupuncturist, Accord Medical Clinic. MBBS (NUS), Graduate Diploma in Family Medicine (NUS), Graduate Diploma in Acupuncture (Singapore College of TCM).
Last reviewed: September 2026
This page is general health education, not medical advice. Whether any treatment is appropriate for you is a decision made in consultation after assessment.
