High Incidence of Benign Perianal Disorders After Sleeve Gastrectomy and One Anastomosis Gastric Bypass.

Aim: Bariatric surgery may alter bowel habits, potentially leading to new-onset benign perianal disorders (NOPD). This study aimed to assess the incidence and identify potential risk factors of NOPD following vertical sleeve gastrectomy (VSG) and one anastomosis (mini) gastric bypass (OAGB).

Methods: We conducted a retrospective cross-sectional, single-center study using retrospective analysis of prospectively collected data. All patients who underwent VSG or OAGB between 2015-2018 were considered. NOPD diagnoses were based on physical examinations and a standardized phone questionnaire assessing past and present perianal symptoms.

Results: Of 540 eligible patients, 313 participated (150 VSG, 163 OAGB). Among 264 patients without prior perianal disorders, 96 (36.4%) developed NOPD postoperatively-29.6% in the VSG group vs. 42.4% in the OAGB group (p = 0.04). The most common conditions were hemorrhoidal disease (24.2%), fissures (12.8%), and abscesses/fistulas (3%). Surgical treatment was required in 17.7% (17/96) of affected patients. Increased bowel movement frequency was more common after OAGB than VSG (57.7% vs. 11.7%, p < 0.001). OAGB, younger age, and altered bowel habits were associated with higher NOPD risk. Forty-nine patients (15.7%) reported preexisting perianal disorders, 26.5% of whom experienced worsening symptoms. Overall, 86% of patients were unaware of the link between bariatric surgery and NOPD, and 15% indicated they would not recommend surgery due to these symptoms.

Conclusion: NOPD are relatively common after bariatric surgery, particularly OAGB. Patients-especially those with identified risk factors-should be counselled regarding this potential complication during the preoperative decision-making process.