A small bump at the anal opening may be an anal fistula. It feels like a small hard knot, and there may be discharge around this small knot when pressed. If you are drinking alcohol, after eating spicy and stimulating food you may also have pain and swelling. If this is the case, it should be an anal fistula. You can touch it yourself to see if you can feel a small hard knot or strip of a cord, if this is the case, it is definitely an anal fistula. In addition, there is another situation where a small bump may be a hemorrhoid, if it is a hemorrhoid, it does not hurt or itch to touch, it is just an extra piece of flesh that grows out. If there are no symptoms, no pain, no itch, you can also leave it alone. If it is not a hemorrhoid but an anal fistula, it is advisable to go to the hospital early to get rid of it, because an anal fistula is prone to repeated infections, and it may aggravate the condition, and a simple anal fistula becomes a complex anal fistula, and a low anal fistula becomes a high anal fistula.