Differential Diagnosis for Constipation and Rectal Bleeding in a 7-Month-Old
Single Most Likely Diagnosis
- Anal Fissure: This is a common cause of rectal bleeding in infants, often associated with constipation. The pain from the fissure can lead to further constipation, creating a cycle.
Other Likely Diagnoses
- Constipation with Hemorrhoids: Although less common in infants, hemorrhoids can occur and cause rectal bleeding, especially if the constipation is severe.
- Gastroenteritis: Infections can cause both constipation (due to dehydration or specific pathogens) and rectal bleeding, though the latter is more commonly associated with diarrhea.
- Cow's Milk Protein Allergy: This can cause a range of gastrointestinal symptoms, including constipation and rectal bleeding, in infants.
Do Not Miss Diagnoses
- Intussusception: A medical emergency where a part of the intestine slides into an adjacent part, which can cause intestinal obstruction and ischemia. It's a rare cause of constipation and rectal bleeding but is critical to diagnose early.
- Hirschsprung's Disease: A congenital condition characterized by the absence of ganglion cells in the distal bowel, leading to severe constipation. While it typically presents at birth, some cases may not be diagnosed until later.
- Infectious Colitis: Certain bacterial infections (e.g., Salmonella, Shigella) can cause severe colitis, leading to both constipation (in the early stages) and rectal bleeding.
Rare Diagnoses
- Juvenile Polyps: These are benign growths in the colon that can cause rectal bleeding, though they are less common in infants.
- Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis are rare in infants but can present with constipation and rectal bleeding among other symptoms.
- Congenital Anomalies of the Rectum or Anus: Conditions such as anorectal malformations can cause constipation and may be associated with rectal bleeding, though these are usually identified at birth or shortly after.