Letrozole and norethisterone acetate in colorectal endometriosis

Objective: Up to now limited attention has been given to the medical treatment of bowel endometriosis. This study evaluates the efficacy of aromatase inhibitors and norethisterone acetate in treating pain and gastrointestinal symptoms caused by bowel endometriosis. Study design: This prospective pilot study included six women with colorectal endometriosis; all women had intestinal nodules infiltrating at least the muscularis propria of the bowel and did not have a stenosis of the bowel lumen >60%; the patients suffered from pain and intestinal symptoms. The study subjects received letrozole (2.5 mg/day) and norethisterone acetate (2.5 mg/day) continuously for 6 months. The presence and intensity of symptoms were evaluated before starting the treatment, and after 3 and 6 months of treatment. Results: The double-drug regimen improved pain, non-menstrual pelvic pain, deep dyspareunia, dyschezia, symptoms mimicking diarrhoea-predominant irritable bowel syndrome, intestinal cramping, abdominal bloating and passage of mucus in the stools, and 67% of the patients declared that the treatment improved their gastrointestinal symptoms. Conclusions: The administration of letrozole and norethisterone acetate reduces pain and gastrointestinal symptoms of women with colorectal endometriosis, particularly when patients suffer from symptoms mimicking diarrhoea-predominant irritable bowel syndrome.