While patients with itchy bottoms are a regular presentation in a colorectal surgery office, patients with sore bottoms are more common. Like an itchy bottom, a sore bottom has a long list of differential diagnoses (Figs. 25.1, 25.2, 25.3, and 25.4). Making the correct diagnosis is obviously the key to effective treatment, and the process begins during the interview. Tables 25.1 and 25.2 present a list of common causes of a painful anus with features that help to make the diagnosis from the history and anal inspection alone. Most sore bottoms can be classified into those with a “lump” and those without a “lump.” Common “lumps” are thrombosed external hemorrhoids, prolapsed internal hemorrhoids, and abscesses. These are usually obvious on a cursory external inspection. If anal inspection in the office does not reveal a “lump,” the most common diagnosis is anal fissure, where the pain is coming from internal sphincter spasm. Gentle anal distraction may reveal the edge of the fissure and/or a sentinel tag. If nothing is seen, empiric treatment with heat and a nitrous oxide donor can be used, or an exam under anesthesia is scheduled. Alternatively, an anal block is performed to relax the internal sphincter and allow an office anoscopy. This is particularly useful if the suspected diagnosis is an anal fissure, but the anus is too “shy” to allow a look inside.