Diagnosis of fecal incontinence

The diagnostic process of fecal incontinence has to assess the severity of the incontinence and the pathophysiological mechanisms involved, in order to propose the most effective and efficient therapy in each case. In general, the following points and factors will be taken into account:

• Clinic history.
• Basic diseases.
• Previous surgeries in the anorectal region (hemorrhoidectomy, sphincterectomy, fissures, prostatectomy, colon resection).
• History of irradiation of the area (prostate cancer, cervical cancer).
• Obstetric history (deliveries, other antecedents).
• Drugs (especially laxatives).
• Circumstances in which incontinence began (eg, after surgery or stroke).
• Characteristics of stools (liquid or more formed).
• Existence of pathological products in the stool (blood, mucus or pus).
• Anal symptoms, warning sensation of passing stool, abdominal pain, feeling of urgency or rectal urge.
• Nocturnal dominance or relationship with some type of food.
• Functional situation (mobility, cognitive impairment), presence of architectural barriers that make access to the bathroom difficult.
• In patients with diarrhea, try to delve into the cause, taking into account the possibility of infection by Clostridium difficile, when there is previous use of antibiotics.

Physical exploration

General examination: abdomen, hydration, mobility.

• Mental and cognitive state, neurological examination.
• Rectal examination Essential. Assess the tone of the anal sphincter, both at rest and during voluntary contraction, the presence of masses, impacted stools, scars, prolapses, pain on examination.

Supplementary tests

Simple X-ray of the abdomen. It is essential to rule out fecal impaction, even in patients with an empty rectal bleb (high impaction).

• Anoscopy It allows evaluating the existence of masses, hemorrhoids, fissures, papillitis and even discovering blood, mucus or pus.
• Dull enema. Aimed at detecting mechanical causes.
• Rectosigmoidoscopy. Assessment of the status of the rectal ampulla and of the alterations in its coloration, ruling out structural diseases, such as polyps, neoplasms or diverticula.
• Defecography. Radiological “videotape” record of defecation. Useful for the knowledge of the anatomical factors involved and their visualization of rectal prolapse.
• Endoanal ultrasound. It allows to view the sphincter apparatus and the puborectalis muscle in a non-invasive way.
• Functional study:
  • Manometry It allows to know the pressure changes at different rectal levels and the anal canal during the defecation process. Useful to assess sphincter trauma.
  • Anal electromyography. To locate changes in the pudendal and sphincters. Rectal sensitivity techniques.

Despite this battery of assessments and diagnostic tests, it is necessary to individualize in each case to indicate the relevant tests. For example, in a patient with dementia and immobilized, we will perform a rectal examination and symptomatic treatment, since more aggressive treatments that require the collaboration of the patient will not be able to be carried out or will not be effective. However, in a multiparous woman with a good baseline situation, who presents an anal sphincter with a decreased tone, we will indicate an endoanal ultrasound to assess a possible surgical intervention or other therapeutic actions.