It borders another muscle known as the Sphincter Ani Externus. Together these muscles seal the anal cavity and expel fecal matter. They play an important role in bowel continence. When the Sphincter Ani Externus is not working correctly, it may cause liquid fecal incontinence or mucous rectal discharge. Damage to the Sphincter Ani Externus may occur during childbirth or anal and rectal surgery. These muscles can also become weak with age.
The Sphincter Ani Internus is often called the Internal Anal Sphincter. This is also known by the acronym IAS.
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However, pain can be alleviated with practice. It’s always advisable to use lubricant during anal sex. Experimenting with anal fingering, anal vibrators, or butt plugs can also help your body become prepared for pleasurable anal sex. It’s important to use only sex toys designed for anal insertion because they will not become lost in the anal cavity.