Differential Diagnosis for Bright Red Blood after Passing Gas
- Single most likely diagnosis
- Hemorrhoids: This is the most common cause of bright red blood per rectum, especially if it occurs after passing gas or stool. Hemorrhoids are swollen veins in the lowest part of the rectum or anus, and they can bleed when irritated.
- Other Likely diagnoses
- Anal fissure: A small tear in the lining of the anus can cause pain and bleeding, especially after passing a hard stool or gas.
- Rectal prolapse: A condition where the rectal mucosa prolapses through the anus, which can cause bleeding and discomfort.
- Inflammatory bowel disease (IBD): Conditions like ulcerative colitis or Crohn's disease can cause rectal bleeding, although it's often accompanied by other symptoms like diarrhea, abdominal pain, and weight loss.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Colorectal cancer: Although less common in younger individuals, colorectal cancer can present with rectal bleeding, and it's crucial to rule out this diagnosis, especially in older adults or those with a family history.
- Gastrointestinal bleeding from a upper source (e.g., diverticulosis, angiodysplasia): Although the blood is bright red, suggesting a lower GI source, it's essential to consider upper GI sources, especially if the patient has other symptoms like abdominal pain or a history of bleeding disorders.
- Infection (e.g., rectal gonorrhea, rectal tuberculosis): Certain infections can cause rectal bleeding and must be considered, especially in high-risk populations.
- Rare diagnoses
- Rectal varices: Enlarged veins in the rectum, often associated with liver disease, can cause bleeding.
- Vascular malformations (e.g., arteriovenous malformations): Rare congenital or acquired conditions that can cause rectal bleeding.
- Intussusception: A condition where a part of the intestine telescopes into another part, which can cause bleeding and obstruction, although it's more common in children.