Loss of gas and occasional liquid stool during initial assessment is most consistent with which type of incontinence and sphincter damage?

• A. Passive incontinence & internal anal sphincter damage.
• B. Flatus incontinence & internal anal sphincter damage.
• C. Urge incontinence & external anal sphincter damage.
• D. Transient incontinence & external anal sphincter damage.

Answer: (B)

The key idea is resting anal pressure and passive continence. The internal anal sphincter provides most of the anal resting tone, keeping gas and liquid stool from leaking without a conscious squeeze. When this sphincter is damaged, the ability to maintain closure at rest is reduced, so gas (flatus) leaks more readily and liquid stool can slip out, especially since liquid stool requires less controlled containment than formed stool.

Urgent or urge-related incontinence involves detrusor (bladder) overactivity, which isn’t about the anal sphincters, and external anal sphincter damage typically disrupts voluntary squeeze and is more associated with leakage that occurs with effort, or with leakage of formed stool when trying to hold it. Transient incontinence is usually due to a temporary factor like illness or medications, not a lasting sphincter injury.

Thus, loss of gas and occasional liquid stool on initial assessment best fits flatus incontinence due to internal anal sphincter damage.