Faecal incontinence

Neurological Causes

Stroke: May cause loss of rectal sensation or control, especially if the stroke affects the frontal lobe or the brainstem.
Multiple Sclerosis: Progressive neurological disease affecting sphincter control, often associated with other neurological deficits.
Spinal Cord Injury: Loss of control below the level of the lesion, often associated with urinary incontinence as well.
Cauda Equina Syndrome: Compression of the cauda equina nerves, leading to incontinence, saddle anesthesia, and lower limb weakness.
Diabetic Neuropathy: Chronic diabetes can lead to autonomic neuropathy, affecting bowel control.
Parkinson’s Disease: Degenerative condition with associated motor dysfunction and potential loss of bowel control.

Muscular Causes

Anal Sphincter Injury: Often due to obstetric trauma, surgery, or traumatic injury leading to weakening of the sphincter.
Pelvic Floor Dysfunction: Associated with childbirth, chronic straining, or pelvic surgeries leading to loss of control.
Rectal Prolapse: Weakening of the rectal support structures can lead to incontinence, often associated with a visible prolapse.
Irritable Bowel Syndrome (IBS): Can cause urgency and occasional incontinence, especially with diarrhea-predominant IBS.
Chronic Constipation: Long-term straining can weaken the pelvic floor muscles, paradoxically leading to overflow incontinence.
Congenital Disorders: Conditions like spina bifida or imperforate anus that affect the development and function of bowel control mechanisms.

Inflammatory and Infective Causes

Inflammatory Bowel Disease (IBD): Crohn’s disease and ulcerative colitis can cause urgency and incontinence, often with bloody diarrhea.
Gastroenteritis: Infective causes leading to diarrhea and transient incontinence, often accompanied by fever and abdominal pain.
Diverticulitis: Inflammation of diverticula in the colon can lead to altered bowel habits and occasional incontinence.
Radiation Proctitis: Inflammation and scarring of the rectum following radiotherapy, leading to urgency and incontinence.

Other Causes

Fecal Impaction: Severe constipation leading to overflow incontinence as liquid stool leaks around the impacted mass.
Drugs: Medications like laxatives, antibiotics, or anticholinesterases can lead to diarrhea and incontinence.
Dementia: Cognitive impairment can lead to loss of awareness and control over bowel function.
Rectal Tumors: Obstructive masses in the rectum can cause altered bowel habits and incontinence.
Psychiatric Disorders: Conditions such as severe depression or schizophrenia can contribute to incontinence through neglect or lack of awareness.
Congenital Anomalies: Conditions like Hirschsprung’s disease can lead to chronic constipation and overflow incontinence.

Onset and Duration

Acute onset: Suggests an infective cause, acute neurological event (e.g., stroke), or fecal impaction.
Gradual onset: More consistent with chronic conditions like neurological diseases, pelvic floor dysfunction, or dementia.
Intermittent vs Continuous: Intermittent may suggest overflow incontinence or IBS; continuous may suggest a more severe neurological or structural cause.

Stool Characteristics

Associated Symptoms

Abdominal pain: Suggests IBD, IBS, or infectious causes.
Fever: Typically present in infectious or inflammatory conditions like gastroenteritis or diverticulitis.
Weight loss: Consider malignancy, IBD, or chronic infection.
Urinary symptoms: May co-exist with pelvic floor dysfunction or neurological causes.
Neurological deficits: Consider spinal cord lesions, stroke, or multiple sclerosis.
Previous surgeries: Obstetric, anorectal, or pelvic surgeries may be relevant to muscle or nerve injury.

Background

Past Medical History: History of neurological conditions, diabetes, chronic constipation, or previous surgeries.
Drug History: Medications that may cause diarrhea (laxatives, antibiotics) or affect neurological function.
Family History: Hereditary conditions like spina bifida or neurodegenerative diseases.
Social History: Recent travel (infective causes), alcohol use, mobility issues, or cognitive impairment.

Blood Tests

Full Blood Count: To assess for infection, anemia, or hematological causes of symptoms.
C-Reactive Protein/ESR: Elevated in inflammatory or infective conditions such as IBD.
Thyroid Function Tests: To rule out hypothyroidism which can contribute to constipation and overflow incontinence.
Urea and Electrolytes: To assess renal function and electrolyte imbalance, particularly in dehydration or chronic diarrhea.
Blood Glucose/HbA1c: Important in patients with diabetes to evaluate for diabetic neuropathy.
Coeliac Serology: Consider in cases of chronic diarrhea and malabsorption.

Stool Tests

Stool Culture: To identify infective agents in cases of suspected gastroenteritis.
Faecal Calprotectin: Elevated in inflammatory bowel disease, helps differentiate from IBS.
Stool Occult Blood: Useful in screening for colorectal cancer or assessing for GI bleeding.
Stool Elastase: To assess for pancreatic insufficiency in cases of malabsorption.
Ova, Cysts, and Parasites: To detect parasitic infections, particularly in patients with recent travel history.

Imaging

MRI/CT Scan of the Spine: Indicated if neurological causes such as spinal cord compression or cauda equina syndrome are suspected.
Endoanal Ultrasound: To evaluate anal sphincter integrity, particularly after obstetric trauma or surgery.
Flexible Sigmoidoscopy/Colonoscopy: Useful in identifying structural lesions like tumors, strictures, or inflammatory changes.
Defecating Proctography: A dynamic study to assess pelvic floor dysfunction and rectal prolapse.
Barium Enema: May be used in chronic constipation to evaluate for anatomical abnormalities.

Electrophysiology

Nerve Conduction Studies/EMG: To assess the function of the anal sphincter and pelvic floor muscles.
Pudendal Nerve Terminal Motor Latency: A test to evaluate the function of the pudendal nerve, which is involved in continence.
Anal Manometry: To measure the pressure within the anal canal and assess sphincter function.

Gastrointestinal