What is the cause of hematochezia (passage of bright red blood per rectum)?

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Differential Diagnosis for Bright Red Blood Per Rectum

  • Single Most Likely Diagnosis
    • Hemorrhoids: This is often the most common cause of bright red blood per rectum, especially if the bleeding is associated with bowel movements or straining. Hemorrhoids are swollen veins in the lowest part of the rectum or anus, which can bleed easily due to increased pressure.
  • Other Likely Diagnoses
    • Anal Fissure: A small tear in the lining of the anus can cause bright red bleeding, especially during or after bowel movements. The pain associated with an anal fissure can distinguish it from hemorrhoids.
    • Diverticulosis: This condition involves the formation of small, bulging pouches (diverticula) in the digestive tract. When these pouches bleed, they can cause bright red blood per rectum, though the bleeding is often more significant and can be associated with diverticulitis.
    • Rectal Ulcer: An ulcer in the rectum can cause bleeding, which may appear as bright red blood per rectum. The presence of other symptoms like pain or a history of similar conditions can help in diagnosing.
  • Do Not Miss Diagnoses
    • Lower Gastrointestinal Malignancy (e.g., Rectal Cancer): Although less common, any rectal bleeding warrants consideration of malignancy, especially in older adults or those with risk factors (family history, previous cancer, etc.). Early detection is crucial for effective treatment.
    • Inflammatory Bowel Disease (IBD): Conditions like ulcerative colitis or Crohn's disease can cause rectal bleeding, among other symptoms such as diarrhea, abdominal pain, and weight loss. Missing these diagnoses can lead to significant morbidity.
    • Angiodysplasia: These are vascular malformations of the gastrointestinal tract that can cause bleeding. They are more common in the elderly and can be a source of significant, sometimes recurrent, bleeding.
  • Rare Diagnoses
    • Arteriovenous Malformation (AVM): A rare condition where there's an abnormal connection between arteries and veins, which can cause bleeding. AVMs in the rectum are exceedingly rare but can be a source of bright red blood per rectum.
    • Dieulafoy's Lesion: A rare cause of gastrointestinal bleeding characterized by a small mucosal defect with an exposed, often large, caliber artery at its base. It's rare in the rectum but can cause significant bleeding.
    • Solitary Rectal Ulcer Syndrome: This condition involves the presence of one or more ulcers in the rectum, often associated with chronic constipation, straining during bowel movements, or rectal prolapse. It can cause rectal bleeding, among other symptoms.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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