Anorectal manometry is a clinical test performed to help diagnose problems with the anal sphincter. Patients who have frequent incontinence issues or chronic, severe constipation may be scheduled for the exam. During anorectal manometry, a doctor inserts a small catheter into the anus and measures pressures when the patient strains and rests. Pressure readings are used to determine how well the sphincter muscles are working. The results allow experts to gauge the severity of problems and choose the best individualized treatment plans.
Many people who suffer from fecal incontinence issues do so because their sphincter muscles are either too weak or the nerves that feed them do not function correctly. Conversely, chronic constipation can be due to over-tightened sphincter muscles and increased nerve activity. A patient who exhibits lasting symptoms of either disorder may be scheduled for a pair of tests, anorectal manometry and electromyography (EMG), to see exactly where their problems lie. The tests can usually be performed in less than one hour in an outpatient setting.
On the day before a patient is scheduled for anorectal manometry, he or she is instructed to use an over-the-counter enema solution to thoroughly clean the bowels. Before the actual procedure, the patient dons a hospital gown and lies on his or her side. The doctor then prepares a sterile catheter with a small balloon attached to one end. The catheter is gently inserted into the anus, and the balloon is slightly inflated. A digital or analog meter on the other end of the catheter provides feedback during the test.
The patient is instructed to strain for a few seconds as if trying to have a bowel movement, then relax, then squeeze his or her buttocks together tightly. The doctor records pressure readings during the three phases. If an EMG is performed in addition to the anorectal manometry, the same type of straining, relaxing, and squeezing test may need to be repeated with an electric sensor inserted in the anus.
Patients are usually allowed to leave the doctor's office immediately after an anorectal manometry, with no restrictions on their diets or activities. Results are typically available a few days later. The doctor can explain what the results mean and what he or she suggests should be considered for treatment. Sphincter strengthening exercises, relaxation techniques, medications, or surgery may be suggested. A person may need to attend another anorectal manometry screening after a period of treatment to see whether or not it was successful.