What causes bloody diarrhea?

Many people develop severe diarrhea—and even gastrointestinal bleeding—due to unhealthy lifestyle habits in daily life. So, what causes blood in diarrhea?

What Causes Blood in Diarrhea?

The presence of both diarrhea and blood is primarily associated with two categories of conditions: gastrointestinal disorders and anorectal diseases. Common gastrointestinal causes include upper gastrointestinal bleeding, peptic ulcers, and colitis. Anorectal conditions such as hemorrhoids and anal fissures may also produce similar symptoms. Careful observation of the characteristics of rectal bleeding during diarrhea can significantly aid diagnosis. It is strongly recommended that patients seek prompt medical evaluation—ideally at a gastroenterology or proctology clinic. Diagnostic tests typically include a complete blood count (CBC), routine stool analysis, fecal occult blood test (FOBT), digital rectal examination, and/or anoscopy. Once the underlying cause is identified, targeted treatment can be initiated.

Colorectal cancer is a malignant tumor that not only invades colonic tissue but, particularly in advanced stages, leads to mucosal erosion and ulceration of the intestinal wall. When stool passes over the tumor site, it may irritate the lesion and trigger hematochezia (bright red blood in stool).

If this condition is suspected, immediate medical consultation is essential. A physician will assess the individual’s specific clinical presentation and recommend appropriate management strategies. Dietary modifications are equally important: patients should avoid spicy, stimulating, and seafood-based foods, as these may exacerbate symptoms. Adequate rest is also crucial. We hope this information proves helpful to you!