Will nystatin cure an anal yeast infection? and what are symptoms of a anal yeast infection

Depends: Nystatin is a cream so will heal where is applied. If the candidosis involves the anal canal it is unlikely to be healed this way. Yeast infection will manifest as pruritus, burning, discomfort. All this symptoms can be cause by so many other conditions. So my advice is to go see your pcp as first intention.

Oral Nystatin: Oral Nystatin will kill the yeast living in your digestive system and that recontaminates the affected area. Probiotics, yogurt & acidophilus milk will provide bacteria to help restore microbiological balance to the gut. If this doesn't work it may be time to see a physician to check your immune system.