What causes rectal bleeding during bowel movements?

Blood in the stool is a common symptom of gastrointestinal disorders, yet some individuals underestimate its significance. It is widely known that bloody stools may signal colorectal cancer—the most serious potential concern. This is especially critical among older adults; blood in the stool should never be dismissed casually. However, rectal bleeding does not necessarily indicate colorectal cancer, as it can also occur in numerous other gastrointestinal conditions, such as hemorrhoids, anal fissures, and colonic polyps. So, what causes rectal bleeding during defecation?

What Causes Rectal Bleeding During Defecation?

Rectal bleeding during bowel movements may stem from colonic diseases—including tumors, polyps, or inflammation in the sigmoid colon, rectum, or at the sigmoid-rectal junction—leading to localized bleeding that manifests as blood from the anus during defecation. Secondly, it may result from rectal disorders, commonly including rectal cancer, rectal gastrointestinal stromal tumors (GISTs), hemorrhoids, and rectal polyps—all of which can cause bleeding during bowel movements. Additionally, systemic conditions such as thrombocytopenia or coagulation disorders (e.g., bleeding diatheses) may also present with concurrent rectal bleeding during defecation.

The most common cause of rectal bleeding during defecation is hemorrhoids. Hemorrhoids are the most prevalent anorectal disorder, occurring at any age but with increasing incidence as people grow older. Chronic alcohol consumption and frequent intake of spicy foods are known risk factors for developing hemorrhoids. Sitz baths with warm water can improve local circulation and help reduce bleeding. Prolonged or recurrent bleeding may lead to iron-deficiency anemia. Patients are advised to drink plenty of water, consume ample vegetables and fruits, maintain regular and soft bowel movements, avoid prolonged sitting, and regularly perform pelvic floor (anal sphincter) contraction exercises to help prevent hemorrhoid recurrence.

If rectal bleeding occurs during bowel movements, it is strongly recommended to seek medical evaluation at a hospital. Under a physician’s guidance, diagnostic tests—such as colonoscopy—should be performed to establish an accurate diagnosis and initiate targeted treatment. We hope this information proves helpful to you.