The diagnosis of anal sinusitis relies mainly on anorectal diagnosis and anoscopy. On anorectal examination, the anal canal is usually constricted, and the inflamed anal sinus is painful to palpation, with hard nodules or depressions, and sometimes hardened anal papillae. During anoscopy, the diseased anal sinus can be seen to be congested and edematous, and the depression in the anal sinus can be deepened, or a small amount of pus or mucus can flow out from the sinus opening.