Differential Diagnosis for Patient with Fever, Diarrhea, Abdominal Pain, and Hematochezia
The patient's presentation of high fever, diarrhea, generalized abdominal pain, and progression to hematochezia and colicky pain suggests an infectious or inflammatory cause. Here's a categorized differential diagnosis:
Single Most Likely Diagnosis
- Infectious Colitis (e.g., Shigella, Salmonella, Campylobacter): The combination of fever, diarrhea, abdominal pain, and hematochezia is highly suggestive of an infectious colitis. These pathogens are common causes of such symptoms and can lead to significant morbidity if not treated promptly.
Other Likely Diagnoses
- Inflammatory Bowel Disease (IBD) Flare: While IBD (Crohn's disease or ulcerative colitis) can present with similar symptoms, the acute onset and progression over a short period might be less typical. However, it's a consideration, especially if there's a history of IBD.
- Food Poisoning: Certain types of food poisoning (e.g., from E. coli, Salmonella) can cause severe gastrointestinal symptoms, including diarrhea, abdominal pain, and potentially hematochezia.
- Diverticulitis: This condition involves inflammation of the diverticula in the colon and can present with abdominal pain, fever, and changes in bowel habits. While less common in younger patients, it should be considered, especially with the progression to hematochezia.
Do Not Miss Diagnoses
- Intussusception: Although more common in children, intussusception can occur in adults and presents with abdominal pain, vomiting, and sometimes bloody stools. It's a surgical emergency.
- Mesenteric Ischemia: This condition involves insufficient blood flow to the intestines and can present with severe abdominal pain out of proportion to physical examination findings, along with other symptoms like diarrhea. It's a medical emergency with high mortality if not promptly treated.
- Appendicitis: While the symptoms might not perfectly align with classic appendicitis, atypical presentations can occur, especially if the appendix is in an unusual location. Appendicitis is a surgical emergency.
Rare Diagnoses
- Ischemic Colitis: This condition involves insufficient blood flow to the colon and can present with abdominal pain and bloody diarrhea. It's less common but should be considered, especially in patients with risk factors for vascular disease.
- Clostridioides difficile (C. diff) Infection: While C. diff can cause severe diarrhea and abdominal pain, hematochezia is less common. However, in the appropriate clinical context (e.g., recent antibiotic use), it should be considered.
- Colonic Vasculitis: This is a rare condition involving inflammation of the blood vessels supplying the colon and can present with abdominal pain, diarrhea, and potentially hematochezia. It's often associated with systemic vasculitis or autoimmune disorders.