Anal<unk>  is caused by crohn's Disease, obstetric injury, retained foriegn body in rectum, radiation proctitis, gonorrhea, HIV, cryptitis, lymphogranuloma venerum,  perirectal abscess sequelae of rupture or surgery, syphilis, thrombosed hemorrhoids, tuberculosis, ulcerative Colitis.
Anal fistula causes
Anal fissure causes
Rectal prolapse causes
Incisional hernia causes
Volvulus causes
Intussusception causes
Appendicular abscess causes
Anal fissure risk factors