What Causes Rectal Bleeding?

Hematochezia (passage of bright red blood per rectum) may result from the following conditions: First, hemorrhoidal bleeding—this is the most common cause, typically presenting as blood mixed with stool or bleeding after defecation, usually in the form of fresh red blood.

Second, ulcerative colitis—characterized by bloody, mucopurulent stools accompanied by abdominal pain; the disease often follows a relapsing-remitting course, and long-standing cases may be associated with weight loss.

Third, gastrointestinal tumors—bleeding caused by colorectal neoplasms is frequently accompanied by changes in bowel habits (e.g., increased frequency, urgency, or constipation) or alterations in stool caliber (e.g., narrowing).

Fourth, hematologic disorders—such as thrombocytopenia or coagulopathies—may also lead to gastrointestinal bleeding and subsequent hematochezia.

The above descriptions are based solely on clinical symptoms. Definitive diagnosis requires further investigations, including colonoscopy and other appropriate diagnostic tests.