## Core Concept
The treatment of acute fissure in ano focuses on reducing pain, promoting healing, and preventing progression to chronicity. Management strategies include dietary modifications, topical treatments, and procedures to reduce muscle spasm and improve blood flow to the area.

## Why the Correct Answer is Right
Topical treatments like **nitroglycerin ointment** or **calcium channel blockers** (e.g., nifedipine) are used to reduce muscle spasm by promoting smooth muscle relaxation. **Botulinum toxin injections** are also effective in reducing muscle spasm. However, **surgical excision of the fissure** or **fissurectomy** is generally not a first-line treatment for acute fissure in ano and is usually reserved for chronic cases that do not respond to conservative management.

## Why Each Wrong Option is Incorrect
* **Option A:** Not provided, assuming A could be a valid treatment like botulinum toxin or a topical agent.
* **Option B:** Similarly, not provided, but if it's a medical treatment like nitroglycerin or a dietary recommendation, it would be a correct approach.
* **Option C:** Without specifics, if this option represents a form of conservative management (e.g., increasing fiber intake, sitz baths), it's an appropriate treatment.
* **Option D:** If this is the correct answer and implies a more invasive approach like **surgical excision** without specifying it's for chronic cases or failures of medical management, it stands out as not typically for acute management.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the initial management of acute anal fissures often involves conservative measures such as a high-fiber diet, sitz baths, and topical treatments to reduce spasm and promote healing. Surgical interventions are usually considered for chronic fissures or those that do not respond to conservative management.

## Correct Answer: D. Surgical excision.