Which conditions are associated with anal fissures?

Anal fissures are often associated with conditions that involve inflammation or damage to the anal canal, which may lead to fissure formation due to increased trauma or pressure in the area. Crohn's disease is an inflammatory bowel disease that can cause chronic inflammation and ulceration in various parts of the gastrointestinal tract, including the anal canal. This inflammation can significantly increase the risk of developing anal fissures.

Tuberculosis, while more commonly affecting the lungs, can also cause extrapulmonary manifestations, including anal and perineal involvement in the form of granulomatous disease, which may lead to the development of fissures.

The other conditions mentioned may not directly cause anal fissures. For instance, while irritable bowel syndrome (IBS) can lead to changes in bowel habits and potential straining during defecation, it is not as commonly associated with fissures as the inflammatory conditions presented in the correct choice. Similarly, diverticulitis primarily affects the colon and is not directly related to anal fissures.

Therefore, the connection between chronic inflammatory conditions like Crohn's disease and tuberculosis with anal fissures comprises the rationale for the choice being correct.