Hi, rather than blaming the colonoscopy for the sexual problems, you can look into certain other more possible causes. Though medical science has yet to find an exact cause-and-effect relationship between enlarged prostate (BPH) and sexual dysfunction, most studies show a significantly higher risk of sexual dysfunction among men with BPH. The drugs prescribed for BPH may potentially decrease ejaculatory function, erectile function, libido, and overall sexual satisfaction. Any impact that BPH medications have on sexual function will typically end when a man stops taking the drug. Look into the following list if any is being used by your boyfriend: Alpha-blockers (Cardura or doxazosin mesylate; Flomax or tamsulosin hydrochloride; Hytrin or terazosin hydrochloride; Minipress or prazosin hydrochloride; and Uroxatral or alfuzosin hydrochloride) Users must also be cautious when taking alpha-blockers with drugs like Viagra or sildenafil citrate because the combination can occasionally produce dangerous drops in blood pressure. Alpha-reductase inhibitors (Proscar or finasteride; and Avodart or dutasteride. Herbal remedies, such as saw palmetto