A patient presents with severe pain during defecation and blood on toilet paper. What is the most likely diagnosis?

The presence of severe pain during defecation accompanied by blood on toilet paper is highly indicative of an anal fissure. Anal fissures are small tears in the lining of the anal canal, typically caused by the passage of hard stools or trauma to the area. The intense pain reported during bowel movements is characteristic of an anal fissure, as the act of stretching the fissure during defecation can lead to significant discomfort.

The blood observed on the toilet paper is often a result of the fissure itself, with bright red blood being common due to the superficial nature of the injury. This aligns with the clinical presentation of a fissure, distinguishing it from other conditions that may cause similar symptoms.

While proctitis, rectal prolapse, and internal hemorrhoids can cause rectal bleeding and discomfort, they typically present with different combinations of symptoms or characteristics. Proctitis may lead to rectal pain and discharge but is less likely to cause the sharp pain associated specifically with defecation. Rectal prolapse involves a protrusion of the rectal tissue and can cause discomfort, but the pain pattern differs from that of an anal fissure. Internal hemorrhoids might cause bleeding and discomfort but are generally not associated with the severe pain described in this