Anal Manometry

Anal manometry is the study of pressures in the anal canal and rectum.

Common indications of anorectal manometry:

  1. If you have stool leakage /fecal incontinence
    1. Postpartum injury - anal tear during delivery or use of forceps
    2. Traumatic injury – road traffic accident / history of fall
    3. Post infection / anal surgery- anal sphincter damage
    4. Diabetes mellitus
  2. If you have constipation/difficulty in passing stools
    1. Poor response to laxatives
    2. Sense of incomplete evacuation
    3. Sense of stool being stuck in the rectum / anal opening
    4. Use finger or jet spray to assist passage of stools
    5. In a child to rule out Hirschsprung's disease
  3. Assessment before biofeedback training
    1. His is done for patients who have stool leakages or constipation
  4. If you have anal or rectal pain and no local cause can be found by your doctors

Procedure:

Usually the doctor will suggest a laxative the night before the procedure to keep your rectum empty. There is no pain during the procedure. There is no sedation required. The procedure takes 15-30 mins to perform.

Anal manometry is done by placing a thin tube in the rectum. The doctor will then give you instructions to hold tight, push and ask if you can feel sensations to pass stools when he inflates a balloon. This test will find out how your rectum pressures are, i.e. can you push adequately while passing stools and if you can relax your anal valve adequately.

If you are not able to relax your anal valve while passing stools then you maybe suffering from pelvic floor dyssynergia or dyssynergic defecation. The treatment for this condition is called biofeedback.

Biofeedback:

In biofeedback anal exercises are taught to the patient on the machine and the patient needs to practice these exercises at home and return to the hospital for multiple sessions to reinforce the correct exercise.

Biofeedback can be of 2 types:

  1. In patients with stool leakage, anal exercises are taught to strengthen the anal muscle and help reduce the leakages
  2. In patients with constipation, anal exercises are taught to relax the anal muscle and help in easier evacuation of stools.

Conclusion

High resolution anorectal manometry is a useful method to help evaluate a patient who has stool leakages or constipation. Biofeedback is a treatment option to strengthen anal muscles in patients with stool leakages. Also biofeedback is a treatment option for patients who have difficulty in stool evacuation.