Clinical Characteristics and Pathophysiology of Fecal Incontinence Mixed With Constipation: An Underrecognized...

Area of Science:

• Gastroenterology
• Colorectal Surgery
• Pelvic Floor Disorders

Background:

• Fecal incontinence (FI) and chronic constipation (CC) are often diagnosed separately, yet many patients experience both.
• The distinct clinical and pathophysiological characteristics of mixed FI and CC (FI-MC) remain unclear.

Purpose of the Study:

• To investigate the clinical and pathophysiological features of FI-MC.
• To compare FI-MC patients with those experiencing FI alone and healthy controls.

Main Methods:

• A retrospective study design comparing 165 FI-MC patients, 184 FI alone patients, and 31 healthy controls.
• Utilized bowel symptom questionnaires, anorectal manometry, balloon expulsion tests, neurophysiology, and anal ultrasound.

Main Results:

• FI-MC patients reported higher prevalence of straining, incomplete evacuation, pain, bloating, digital maneuvers, and enema use than FI alone patients.
• FI patients showed lower anal resting pressure compared to FI-MC and controls. Both FI groups had reduced anal squeeze pressures and prolonged nerve conduction times.
• Dyssynergic defecation was more prevalent in FI-MC, while anal sphincter defects were more common in the FI alone group.

Conclusions:

• Fecal incontinence patients can be classified into two distinct phenotypes: FI alone and FI with chronic constipation (FI-MC).
• Each phenotype exhibits unique clinical characteristics and underlying pathophysiology.
• Recognition of these distinct phenotypes is crucial for optimizing the management of fecal incontinence.