<unk>  is a hernia involving the perineum (pelvic floor). The hernia may contain fluid, fat, any part of the intestine, the rectum, or the bladder. It is known to occur in humans, dogs, and other mammals, and often appears as a sudden swelling to one side (sometimes both sides) of the anus. A common cause of<unk>  is surgery involving the perineum.<unk>  can be caused also by excessive straining to defecate. Other causes include prostate or urinary disease, constipation, anal sac disease (in dogs), and diarrhea. Atrophy of the levator ani muscle and disease of the pudendal nerve may also contribute to a<unk> .
Perineal hernia
Internal hernia
Inguinal hernia
Pseudomeningocele
Retrocolic hernia
Incisional hernia
Fascial hernia
Sigmoidocele