The incidence of post-vasectomy pain can be estimated from available studies in the medical literature. The symptoms are well described by affected patients and there are effective treatments. Chronic genital pain that affects sexual function and quality of life is a catastrophic outcome for the affected men. Having pain with erection, orgasm, or after sex is the most distressing aspect. This outcome affects quality of life, yet it is rarely featured in the informed consent documents or pre-operative dialogue. Information on this issue should be presented at the time of vasectomy. Several studies have concluded that a discussion of chronic post-vasectomy testicular pain is imperative and should be included in the informed consent process (Morris et al 2002, Manikandan et al, 2004). The study by Choe and Kirkemo concluded that chronic scrotal pain was the most common post-vasectomy complication that can adversely affect quality of life (Choe and Kirkemo, 1996). Acute post-vasectomy problems with bleeding or infection have an incidence of approximately 2 to 5% and are usually featured on the consent. The incidence of chronic pain that can affect sexual enjoyment or function is also around 2 to 5%, but it is not often a focus during the consent process. Any vasectomy technique carries a risk of chronic testicular pain - see this reference. The only prospective audit in the literature found an incidence of 15% for testicular pain in the first year after vasectomy. (Leslie et al, 2007) No technique has been proven to cause a lower incidence of chronic testicular or epididymal pain, although the "no scalpel, open" technique does seem to have fewer acute complications.
Vasectomy can cause chronic scrotal, testicular, or groin pain that can interfere with sexual function or sexual enjoyment. Because this outcome can have a significant impact and affect quality of life, it should be featured on vasectomy consent forms. You can see from this study that pain can not only occur, but can be chronic and between 1 in 30 and 1 in 60 men regret vasectomy due to chronic pain. Whether the incidence is one in a thousand or six percent does not matter if you are the affected patient. If a patient is not made aware of this risk pre-operatively and then develops symptoms, a severe, life altering outcome has occurred with no warning. This is simply wrong, and the incidence of the problem does not excuse this omission. The very nature of the affect of chronic pain on the patient’s quality of life necessitates its inclusion in pre-operative dialogue and on the written consent. Vasectomy is an elective procedure with many alternatives and because of this, requires completely informed consent.
Given that many people considering surgery don't fully read the informed consent document used, the best course of action would be direct communication of all risks from the surgeon to the patient during pre-operative counseling. To do less is inadequate informed consent. Given that malpractice litigation regarding vasectomy comprises a disproportionate share of all urology litigation, it follows that complete informed consent would not only be honest, but protective for both parties involved.
Review the outcomes linked here and you will see a range of possible outcomes that are extremely distressing to the affected men.