Obstructed Defecation Syndrome

Obstructed Defecation Syndrome (ODS) is a common problem describing a difficulty in emptying of the bowels. Many of the symptoms are those of constipation, though specifically patients with ODS tend to have:

  • Difficulty in passing motions
  • Repeated (sometimes unsuccessful) visits to the toilet
  • A sensation of incomplete evacuation or blockage.
  • Needing to use a finger in the bottom or vagina to help with bowel emptying.


ODS is frequently caused by the structural abnormalities associated with a weak pelvic floor or ‘prolapse disease’ such as intussusceptionrectal prolapseenterocoele or rectocoele. These may be the result of pregnancy or childbirth, excessive straining or a congenital disorder (a defect you have had since birth). Often symptoms appear or worsen with age as connective tissue becomes looser.

Less commonly (about 5-10%), a tight pelvic floor (anismus) is the cause.


The usual tests are a flexible sigmoidoscopy or colonoscopy to look for a problem of the bowel itself and anorectal physiology and endoanal ultrasound to assess the state of the sphincter muscle. A defaecating proctogram usually shows why patients are struggling to empty their bowels. A transit study will identify those patients with slow transit constipation. Some patients have both ODS and slow transit.

It is essential that sufficient diagnostic testing is carried out to identify exactly where the problem lies, as treatment of the symptoms of ODS without addressing the root cause may not lead to improvement.


Many patients will benefit from simple measures including dietary changes and pelvic floor retraining. These ‘conservative’ treatments require some effort but can be surprisingly successful, often keeping symptoms sufficiently under control such that patients find that they do not affect quality of life, sometimes providing enough improvement to completely resolve the problem.

Patients who do not improve with these measures may benefit from surgery to correct an underlying anatomical problem. Common operations that our surgeons undertake include laparoscopic ventral rectopexy or transanal repair by STAMP or STARR.

Please be advised that the information on this website is not a substitute for professional medical advice, diagnosis or treatment