Scientific Review on Incomplete Emptying

In this scientific review you will learn more about incomplete emptying causes and treatment.

Incomplete emptying

Patients report incomplete emptying as one of the most bothersome symptoms of constipation [1] and evacuation difficulties causing incomplete emptying also commonly cause faecal incontinence. A common cause of evacuation difficulties is pelvic floor dysfunction that refers to different symptoms and anatomic changes related to abnormal function of the pelvic floor.

Globally, it is an increasing problem due to the ageing population, affecting millions of, mainly, women every year [2]. Included in pelvic floor dysfunctions are pelvic floor dyssynergia and pelvic organ prolapse (POP) that commonly co-exist also with a rectocele.  The symptoms have a great impact on quality of life and restricts social activities, employment, and relationships. Creating a manageable situation of the symptom can significantly improve quality of life. Many try to manage their symptom by themselves due to embarrassment and the taboo around bowel dysfunction [3]. This is partly shown by the common use of self-digitation to assist evacuation when having pelvic floor dysfunctions. Unfortunately, self-digitation may cause anorectal ulcerations with bleeding, discomfort and anal fibrosis that potentially could lead to stricture [4].

Pelvic Organ Prolapse (POP)

POP is a collection name for disorders in which one or more of the pelvic organs drop from their normal position due to weakened or damaged tissue or muscles. The pelvic organs include the bladder, uterus and cervix, vagina, and rectum. The life-time risk of having POP by age of 80 years has been calculated to be 11.1% whereof 46% affects rectum [5]. Other studies report of an incidence of rectal prolapse to be approximately 2.5 per 100,000 inhabitants with a clear predominance among elderly women [6, 7].

 Rectal prolapse, also called rectal procidentia, appears like [6]:

  • Fecal incontinence
  • Pain during bowel movements
  • Mucus or blood discharge from the protruding tissue
  • Loss of urge to defecate

Treatment of rectal prolapse

Medical treatment helps ease the symptoms of a prolapsed rectum temporarily or to prepare the patient for surgery. Bulking agents, stool softeners, and suppositories or enemas are used as treatment to reduce pain and straining during bowel movements. Surgery to repair rectal prolapse involves attaching or securing the rectum to the posterior part of the inner pelvis and should be restricted to cases with a certain degree of prolapse where conservative treatment options have failed [8].  

Surgery may solve the prolapse, but bowel symptoms may not be improved. In a clinical study with 140 patients at long-term follow-up displayed anatomic cure in 76% and an overall improvement in prolapse symptoms. However, the reported rates of incomplete emptying (from 27% to 38%) and fecal incontinence (from 4% to 11%) were all higher after the surgery [5, 9].

Pelvic Floor Dyssynergia or Obstructed Defecation Syndrome (ODS)

A common subtype of constipation is obstructed defecation that has been reported to occur in about 7% of the adult population [10]. Pelvic floor dyssynergia is when the pelvic floor muscles have an inappropriate or paradoxical contraction or fails to relax. This paradoxical contraction of the puborectal muscle and the external anal sphincter often occurs during attempts to defecate causing obstructed defecation, also called obstructed defecation syndrome (ODS), characterized by:

  • Fragmented stools
  • Need for straining at defecation
  • Sense of incomplete evacuation
  • Urgency and tenesmus (continual or recurrent urge)
  • Pelvic heaviness
  • Self-digitation: compression through vagina or pushing on the perineum

The underlying anatomical and pathophysiological changes are complex in ODS. Rectocele, rectal prolapse and rectal intussusception are common anatomical disorders associated with ODS; rectocele and rectal prolapse are present in more than 90% of patients with ODS [4].

There is no gold standard for the diagnosis of ODS, but balloon expulsion test can confirm diagnosis and there are several ODS scores for severity [11].

Treatment of obstructed defecation

ODS may not be responsive to treatment with laxatives and dietary fiber [10]. However, there are other conservative treatment options that can be used before considering surgery. Many studies on surgical treatment of ODS have not tried those options before surgery is proposed, displaying a tendency oflly overtreatment where half of the patients undergo surgery before trying conservative measures [4]. For ODS, treatment recommendations usually are to start with biofeedback [4, 5, 10]. Biofeedback has been reported to be beneficial in more than half of patients with pelvic floor dyssynergia, but most data are from uncontrolled studies with different protocols and selection criteria. Still, most studies show good short-term results whereas the few long-term studies indicate a fading effect over time [10]. However, it remains to be evaluated if biofeedback in combination with other treatment options can result in better clinical outcome.

Rectal irrigation, also called transanal irrigation (TAI), is reported to be effective in about 50% of patients with constipation and fecal incontinence [4]. There are a variety of irrigation devices available with either cone or self-retaining catheters that can deliver different volumes of water for completing emptying of rectum and/or distal colon [12]. For incomplete evacuation, passive fecal incontinence including post-defecation soiling, and rectocele it is usually enough to use a low volume of water (a low volume is usually below 250 ml) to relief symptoms [12].



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