Anorectal disorders are commonly encountered in the practice of emergency medicine. Most can be diagnosed and treated in the emergency department setting. Almost all anorectal disorders once diagnosed and treated in the emergency department need appropriate follow-up to ensure adequacy of treatment, for further possible diagnostic procedures (e.g., endoscopy, biopsy), or for definitive treatment. Hemorrhoids are the most prevalent anorectal disorder and are the most common cause of hematochezia. Treatment is dependent on the degree of hemorrhoid prolapse and symptoms. Most cases can be treated by conservative medical treatment (e.g., dietary changes, sitz baths) or nonsurgical procedures (e.g., rubber band liagation, infrared coagulation). Surgical excision of symptomatic thrombosed external hemorrhoids is indicated if within 48 to 72 hours of pain onset. Anal fissures are one of the most common causes of anorectal pain. They are most frequently idiopathic, and most are located in the posterior midline of the anal canal. Most anal fissures are adequately treated by a medical approach using sitz baths, stool softeners, and analgesics. If the anal fissure becomes chronic and is not responsive to medical therapy, a lateral sphincterotomy of the internal anal sphincter is the surgical procedure of choice. Pharmacologic treatment (botulinum toxin or nitroglycerin ointment) to decrease internal anal sphincter tone has shown promise in the treatment of anal fissure. Anorectal abscesses are categorized into four types: perianal, ischiorectal, intersphincteric, and supralevator. Most are idiopathic and contain mixed aerobic-anaerobic pathogens. Fistula formation varies from 25% to 50% and is much more common with gut-derived organisms (e.g., E. coli, B. fragilis). Definitive treatment for an anorectal abscess is timely surgical incision and drainage to prevent more serious complications (e.g., serious infection, extension of the abscess). Anal carcinomas are infrequent, the majority of them being squamous cell or epidermoid carcinomas. The emergency physician must maintain a high index of suspicion and obtain a biopsy of suspicious lesions in order not to miss the diagnosis of a cancer. The most common presenting complaint of anal tumors is rectal bleeding. Combination chemotherapy and radiotherapy have shown promising results in the treatment of anal canal tumors. Bacterial, viral, and protozoal infections can be transmitted to the anorectum via anoreceptive intercourse. Such infections must be considered when a patient presents with rectal pain or discharge, tenesmus, or rectal or perineal ulcers. Proctosigmoidoscopy and rectal cultures may be necessary to determine the cause. Potential rectal complications of HIV infection include infectious diarrhea, acyclovir-resistant strains of HSV2, Kaposi's sarcoma, lymphoma, and squamous cell carcinoma. Rectal injuries may result from penetrating or blunt trauma, iatrogenic injuries, or foreign bodies. Rectal injury should be suspected when a patient presents with low abdominal, pelvic, or perineal pain or blood per rectum after sustaining trauma or undergoing an endoscopic or surgical procedure. Tetanus prophylaxis, intravenous antibiotics, and surgical intervention are indicated in all but superficial rectal tears.