Assessment of noninvasive intra-anal electromyography to evaluate sphincter function

Assessment of anal function is now regarded as an important aspect of the proctologic examination in assessment of patients with disordered defecation. Conventional electromyography is invasive and often not repeatable because of patient discomfort. Noninvasive surface intra-anal EMG was evaluated as a method of assessing sphincter function in 76 subjects. A significant correlation was found between intra-anal EMG and anal manometry at rest and during a maximum squeeze effort (P less than 0.01). Intra-anal EMG was found to be reproducible when evaluated by 2 independent observers (P less than 0.05) and may prove a reliable portable noninvasive method of assessing sphincter function.