Inclusion Criteria:  Male between 18 and 65 years old  Will undergo one of the following surgeries in the 12 months after the initial visit:  Low anterior resection Abdominoperineal resection with end colostomy Total proctocolectomy with ileostomy Total proctocolectomy with ileoanal reservoir Proctectomy Having had a sexual intercourse in the 4 weeks prior to the initial visit Having the desire to maintain sexual activities in the post-operative period  Exclusion Criteria:  Tadalafil allergy/hypersensitivity Having received treatment for erectile dysfunction or medical treatment in the 4 weeks prior to the initial visit Active consumption of nitrate derivatives (NO) History of non-arteritic ischemic optic neuropathy Severe renal or hepatic insufficiency Stroke in the last 6 months Myocardial infarction in the last 3 months Unstable angina pectoris or angina pectoris during sexual relations Cardiac insufficiency Class ≥ 2 in the last 6 months Uncontrolled arrhythmia, hypotension or hypertension