Bariatric surgery results in a significant reduction in faecal incontinence (FI) prevalence in women and in particular for those who underwent Roux-en-Y gastric bypass or one anastomosis gastric bypass, according to the outcomes from the first systematic meta-analysis that has assessed both prevalence and frequency of FI in bariatric patients, in both men and women. However, the study authors from by New Zealand researchers from Counties Manukau Health, the University of Auckland, Auckland and the University of Otago, Dunedin, cautioned that the overall FI severity and impact on quality of life were not statistically significant and that larger studies are needed in this under-researched area to determine the true effect of bariatric surgery on FI. The outcomes were featured in the paper, ‘Does Bariatric Surgery Improve Faecal Incontinence? A Systematic Review and Meta-analysis’, published Obesity Surgery.
Although FI is associated with obesity, the effect of bariatric surgery on the prevalence and severity of FI has not been well reported. Therefore, the authors undertook a systematic review to assess the effect of bariatric surgery on the prevalence and severity of FI in adult patients with obesity. In total, 13 studies included (eight assessing prevalence (n=678 patients) and 11 assessing severity of FI (n=1,160 patients).
The mean age of patients was 42.8 years (range 30.7 to 54.8) with the average follow-up time og 12.4 months for prevalence and 20.2 months for severity. Patients underwent five different types of bariatric surgery: 768 (53%) patients had Roux-en-Y gastric bypass, 190 (13%) had gastric banding, 177 (12%) had laparoscopic gastric sleeve, 166 (11%) had one anastomosis gastric bypass, and 29 (2%) had a duodenal switch. The surgery type was not specified in 137 (9%) patients.
Of the 678 patients, 607 (89%) were woman. FI prevalence was measured in a number of ways across the eight papers; three studies used validated questionnaires, and five used researcher-designed questions. FI prevalence reduced from 24.5 to 20.9%, with an average follow-up time of 12.4 months (p=0.075). The change in BMI or age was not significantly associated with prevalence of FI (p=0.24 and p=0.22, respectively).
Of the 678, 390 (58%) underwent Roux-n-Y gastric bypass or mini-gastric bypass, 190 (28%) had gastric banding, 141 (21%) had laparoscopic or open sleeve gastrectomy, and 29 (4%) had a duodenal switch. The authors reported a statistically significant reduction in FI prevalence following Roux-n-Y or one anastomotic gastric bypass (p=0.007). However, there was no statistically significant reduction following sleeve gastrectomy or gastric banding (p=0.59 and 0.21 (0.04 to 1.16), p=0.073, respectively).
The authors noted that although their study reported a statistically significant reduction of FI post-Roux-en-Y gastric bypass and one anastomosis gastric bypass, this could be because Roux-en-Y represented the most common surgery in the published studies. Additionally, they noted bariatric surgery induced weight loss may reduce intra-abdominal and thus anal sphincteric pressure, although improvement in FI after bariatric surgery was independent of weight loss and they hypothesise that there are hidden factors driving the benefit of bariatric surgery on FI in women and gastric bypass patients.
“Further studies are required, particularly in older patients, male patients and multiple ethnic groups. As FI has large psychosocial, physical and financial impacts on patients, it may be an important pre- and post-operative symptom for some patients,” the authors concluded. “By understanding how bariatric surgery will impact FI, surgeons and clinical teams can target treatments and manage expectations of their patients, thus providing better overall care.”
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