Fecal Incontinence - Classification & Severity Scales

Classification & Severity Scales

There is no consensus about the best way to classify FI. There are several methods of classification:

By symptom. FI can be divided into those patients who experience a defecation urge before leakage, termed urge incontinence or experience no sensation, passive FI/soiling. Urge and passive FI may be associated with more severe weakness of the EAS and IAS respectively. Urgency may also be associated with reduced rectal capacity and compliance, and increased rectal sensitivity.

By leakage character. FI forms a continuous spectrum of different clinical presentations from incontinence of flatus (gas), through incontinence of mucus or liquid stool, to solid fecal incontinence. The term anal incontinence often is used to describe flatus incontinence, however it is also used as a synonym for FI generally. Terms such as soiling, fecal soiling, fecal seepage, fecal leakage are often used to describe incontinence of liquid stool and/or mucus. Others however describe a spectrum of severity using these descriptive terms, where staining < soilage < seepage < "accidents". Some refer to solid stool incontinence as complete incontinence, and anything less as partial incontinence:

• Partial incontinence

• Incontinence of flatus (gas)/ anal incontinence
• Incontinence of liquid stool and/or mucus

• Complete incontinence

• Incontinence of solid stool

By age. In children, FI is generally termed encopresis, which refers to involuntary loss of (usually liquid) stool in children over the age of 4 who have been toilet trained. The term pseudoincontinence is used when there is FI in children who have anatomical defects (e.g. enlarged sigmoid colon or anal stenosis). Encopresis is a term that is usually applied when there are no such anatomical defects present. "Soiling" is sometimes used interchangeably with encopresis in pediatric studies.

By gender. FI can also be classified according to gender, since the etiology of FI in females may be different to males, for example FI may develop following radical prostatectomy in males, whereas females may develop FI as a consequence of giving birth.

By presumed primary underlying cause. FI may also be classified according to etiology. The majority of FI patients over the age of 18 fall into one of the following groups:

• Structural anorectal abnormality (sphincter trauma, sphincter degeneration, perianal fistula, rectal prolapse)
• Neurological disorders (multiple sclerosis, spinal cord injury, spina bifida, stroke, etc.)
• Constipation/fecal loading (presence of a large amount of feces in the rectum with stool of any consistency)
• Cognitive and/or behavioural dysfunction (dementia, learning disabilities)
• Loose stools (inflammatory bowel diseases (IBD, e.g. ulcerative colitis, Chron's disease), irritable bowel syndrome (IBS)
• Disability related (patients who are frail, acutely unwell, or have chronic/acute disabilities)
• Idiopathic (self caring adults with FI and none of the above)

Several severity scales fo FI have been suggested. the most commonly used are mentioned below, others include: AMS, Pescatori, Williams score, Kirwan, Miller score, and the Vaizey scale.

Cleveland Clinic (Wexner) fecal incontinence score The Cleveland Clinic Incontinence Score is widely used because it is practical, easy to use and interpret. The score takes into account 5 parameters that are scored on a scale from 0 (=absent) to 4 (daily) frequency of incontinence to gas, liquid, solid, of need to wear pad, and of lifestyle changes.

(Modified) Park's Incontinence score This divides patients with FI into the following categories:

1. continent for solid and liquid stool, continent to flatus
2. continent for solid and liquid stool but not flatus. Some urgency.
3. continent for solid stool, no control of liquid stool/flatus
4. complete incontinence (incontinent to formed stool.)

Fecal Incontinence Severity Index This is based on a type-by-frequency matrix with four types of leakage (gas, mucus, liquid stool, solid stool) and five frequencies (one to three times per month, once per week, twice per week, once per day, twice or more per day.