Differential Diagnosis for Isolated Episode of Painless Blood on Toilet Paper in a 2nd Trimester Pregnant Patient

• Single Most Likely Diagnosis
  • Hemorrhoids: This is a common condition in pregnancy due to increased venous pressure and constipation. The painless nature of the bleeding and its resolution suggest a minor hemorrhoidal bleed, which is often self-limiting.
• Other Likely Diagnoses
  • Anal fissure: Although typically painful, some anal fissures may present with painless bleeding, especially if they are small or superficial. The bleeding is usually minor and may resolve on its own.
  • Rectal mucosal tear: A minor tear in the rectal mucosa can cause painless bleeding, especially if it's small and not associated with significant trauma.
• Do Not Miss Diagnoses
  • Colorectal cancer: Although rare in young pregnant women, colorectal cancer can present with rectal bleeding. It's crucial to rule out this diagnosis due to its severe implications.
  • Inflammatory bowel disease (IBD): Conditions like ulcerative colitis or Crohn's disease can cause rectal bleeding and may be exacerbated by pregnancy. Early diagnosis and management are essential to prevent complications.
  • Gastrointestinal infection: Certain infections, such as those caused by Salmonella or Shigella, can lead to rectal bleeding. Prompt diagnosis and treatment are necessary to prevent severe outcomes.
• Rare Diagnoses
  • Rectal varices: These are dilated veins in the rectum that can cause bleeding, often due to portal hypertension. This condition is rare in pregnancy but can be associated with significant bleeding.
  • Vascular malformations: Rare congenital or acquired vascular anomalies can cause rectal bleeding. These conditions may require specialized evaluation and treatment.
  • Intussusception: A rare condition where a part of the intestine telescopes into another, which can cause bleeding. Although more common in children, it can occur in adults, including pregnant women.