What is Obstructed Defecation Syndrome?

ODS is a functional disorder where patients have difficulty evacuating the rectum despite straining — the stool is present but cannot be expelled. It is characterised by: excessive straining, sensation of incomplete emptying, need for digital assistance (finger assistance to pass stool), and multiple failed attempts. ODS is caused by structural abnormalities: rectocoele (anterior bulge of rectal wall), internal rectal intussusception, or enterocele.

Diagnosis

• Defaecating Proctogram — dynamic X-ray study while the patient attempts defecation; shows rectocoele, intussusception, enterocele
• MRI Defaecography — superior imaging without radiation
• Anorectal Manometry — rules out anismus (paradoxical sphincter contraction)
• Colonoscopy — to exclude structural lesions

Treatment

• Conservative first — high-fibre diet, laxatives, biofeedback for anismus, pelvic floor physiotherapy
• STARR Procedure — Stapled Transanal Rectal Resection; removes excess rectal tissue causing obstruction using circular staplers passed through the anus. Day-care procedure.
• Laparoscopic Ventral Rectopexy (LVR) — fixes the rectal wall to the sacrum with a mesh, correcting rectocoele and intussusception simultaneously. Preferred for complex ODS with combined prolapse.