Diosmin is a flavonoid commonly used in combination with hesperidin for the treatment of venous insufficiency and hemorrhoidal disease. Its use in anal fistula and anal fissure is based on its pharmacological properties, which include improving venous tone, reducing capillary permeability, and exerting anti-inflammatory effects. Several clinical studies and randomized controlled trials have investigated the role of micronized purified flavonoid fraction (MPFF), which includes diosmin, in the management of anal fissures and postoperative symptoms associated with anal fistula surgery.

For anal fissures, controlled studies have shown that diosmin can reduce pain, bleeding, and healing time, especially when combined with conventional treatments like topical nitrates or sitz baths. Its benefits are attributed to improved microcirculation and reduction in local edema and inflammation. Regarding anal fistula, evidence is more limited, but some studies suggest that diosmin may help alleviate postoperative pain, swelling, and promote wound healing when used as adjunctive therapy after surgical interventions.

While systematic reviews confirm modest benefits for acute and chronic anal fissure treatment, the evidence for anal fistula is less robust, mostly limited to small trials and observational studies. Diosmin is generally well tolerated. Therefore, its use is scientifically supported for anal fissure, with moderate evidence, and for anal fistula primarily as an adjunct, with weaker evidence.