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What is Evacuatory Dysfunction?
Evacuatory Dysfunction is difficulty in emptying the rectum that necessitates frequent visits to the toilet. this may contain a constellation of symptoms such as excessive straining at bowel movements, sensation of incomplete evacuation, and the need for finger insertions to help the bowel movements. Its estimated that about 4.6% of the population had symptoms of evacuatory dysfunction. and can be common up to 50% in elderly and weak. Evacuatory dysfunction has significant effects on quality of life as well as major financial implications.
Why does this occur?
Defaecation is a complex process involving various muscles acting in unison using sensory information coming from rectum anus and many other structures which is highly coordinated by central nervous system. Any derangement in this complex system can lead to evacuator dysfunction. These derangements can be either mechanical or functional.
Mechanical causes are situations where the normal arrangement of the ano-rectum is distorted or displaced. This is seen in internal (Rectal Intussusception) or external rectal prolapse. Abnormal pockets of rectum can develop distorting the normal shape of the rectum called rectocoele. Alterations in ano-rectal angle can also cause this problem as well as bulging of the rectal wall in to the lumen due to external pressure from other structures such as bowel (enterocoele). Sometimes the whole pelvic floor becomes weak and increased abdominal pressure during defecation cases the entire pelvic flood to move down without opening up the rectal outflow. This is called pelvic floor descent.
The post-surgery conditions such as anterior resection, ileal pouch, hysterectomy and other pelvic procedures can affect the evacuatory function in various ways – by distorting the anatomy, reducing capacity, affecting compliance, causing nerve disruptions, changing stool consistency and reducing stool transit time.
The mechanical causes can also occur due to weakness of the muscles or as a result of the neurological problem.
The reduced rectal sensation (Hyposensitivity) will lead to increased rectal loading, megarectum, incomplete emptying due to both inadequate feedback and deranged local reflexes. These can lead to secondary consequences like Rectocoele and Rectal intussusceptions and tertiary problems like urgency, faecal incontinence and haemorrhoids.
In some instances, even though the muscles and the rectum appears normal but the cordination of the pelvic muscles and rectal wall doesn’t happen properly so that evacuation is difficult. This is called Pelvic Dys-synergia.
Various other non-bowel factors can also cause evacuatory dysfunction. Some examples are: Systemic Sclerosis, dementia, Ehlers Danlos syndrome, learning disabilities, and medications can affect the evacuation process. These factors act at various levels – higher centers, stool consistency or the muscles and supporting tissues.
What happens if you develop Evacuatory Dysfunction?
There will be progressive deterioration. For example, these can lead to issues such as Megarectum and changes in rectal compliance. The presentation can then be symptoms of lack of rectal filling sensation and incomplete emptying. This can lead to secondary mechanical consequences such as Rectal Intussusception and Rectocoele. The symptoms can then reflect these and include sensation of blockage, vaginal bulge/ pressure. The incomplete emptying can lead to urgency and urge leakage or post defaecation/passive leakage. Further progression of the condition can lead to tertiary consequences such as haemorrhoids, anal fissure, anal skin tags, solitary rectal ulcer syndrome (SRUS) which may cause the presenting complaints.
The symptoms of rectal bleeding or signs of Solitary Rectal Ulcer Syndrome (SRUS) may also create anxieties of any underlying sinister cause. Other consequences are dyspareunia, chronic pelvic pain or bladder symptoms. These are also likely to impact on all aspects of quality of life – personal, social and sexual. The patient is likely to become more and more housebound and detaching themselves from most activities. Finally reduced mobility, depression and low self-esteem may result.
How investigations can help?
Many objective tests are presently available which can support the decision-making process. Evacuatory Proctogram is still the ’gold standard’ to evaluate the anorectal emptying. MR Proctogram is an alternative, which can avoid radiation in the younger patient. The proctogram can help with various information including rectal capacity, rectal sensation, anorectal angles during different states, completeness and time taken for emptying, mechanical issues like rectocoele, rectal intussusceptions, enterocoele as well as functional issues such as dyssynergia.
The anorectal manometry is a useful investigation to help know about the functional competence of anal sphincters, rectal sensation, Recto Anal Inhibitory Reflex (RAIR), length of anal canal and dyssnergia.
The endo-anal ultrasound helps with information about the structural integrity of the anal sphincters, associated conditions such as fistula, sepsis/collections amongst others.
What can be expected in treatment?
It is to be remembered that these problems have a long natural course which are influenced by multiple factors. All of which may not be possible to be corrected. It is hence sensible to identify the most important symptom, so that priorities can be decided.
It is important that the expectations are realistic. It is important to understand that there are no quick fix solutions or guaranteed solutions. Surgical outcome may not be great as one might think and surgery is considered only after non-surgical treatments are tried. The natural course is one of gradual deterioration and hence there is a chance of recurrence even after successful surgery.
What are the Non-Surgical treatments?
This is usually one of the first steps in the management of any patient with pelvic floor dysfunction. The purpose is usually two fold – increase the tone/strength and improve co-ordination. This also combines education regarding defaecation techniques and may help to clarify many questions the patients have regarding their evacuation.
This would be an extension of the above physiotherapy – giving a feed-back to the patient regarding their own body processes. This better understanding leads to more conscious control and efforts to improve the defaecation dynamics. There are several methods used to provide this feedback – manometry, Electromyogram (EMG) and ultrasound. This can be useful in cases of rectal hyposensitivity, rectal hypersensitivity and pelvic dyssynergia.
This can be effective when suppositories/enemas have not been helpful. The symptoms can be reduced sufficiently in order to avoid operations in many patients. This aims to give back control over the bowels back to the patients – who can choose the time and place at their convenience. It is safe and has good patient compliance. Good patient selection and tailored nurse training is the key to success. This can be administered in various ways - High volume (approx 700ml) and Low volume (120ml). In the long run, this is cost-effective and has an established role in management of evacuatory dysfunction.
Whilst this may not have a role in ODS, it can be part of the treatment in mixed cases where faecal leakage/associated sphincter incompetence is also present. A percutaneous method (PTNS) or Sacral Nerve Stimulation (SNS) may be used.
These are mainly useful in the management of Obstructed Defaecation Syndrome (ODS) due to mechanical issues such as Rectocoele, Enterocoele, Rectal Intussusception and Rectal Prolapse.
Laparoscopic Rectopexy: A laparoscopic approach is used which involves releasing, elevating and supporting the rectum by hitching it in place.
An alternative is a perineal approach such as Altemeier’s procedure for full thickness overt prolapse or Delorme’s procedure for mucosal prolapse.
A rectocoele may also require surgery if non-surgical measures are not effective in controlling symptoms. A transvaginal approach is usually used.