Differential Diagnosis for Colitis
The differential diagnosis for colitis can be categorized based on inflammatory and infectious causes. Here's a breakdown of the possible diagnoses:
- Single Most Likely Diagnosis
- Ulcerative Colitis (UC): A chronic inflammatory bowel disease characterized by diffuse inflammation of the colonic mucosa, typically starting in the rectum and extending proximally. Symptoms include bloody diarrhea, abdominal pain, and weight loss. UC is a common cause of colitis and should be considered first due to its prevalence.
- Other Likely Diagnoses
- Crohn's Disease: A type of inflammatory bowel disease that can affect any part of the gastrointestinal tract, causing symptoms like diarrhea, abdominal pain, weight loss, and fatigue. While it can present similarly to UC, the distribution of inflammation and presence of skip lesions can help differentiate it.
- Infectious Colitis (e.g., Salmonella, Shigella, Campylobacter): Bacterial infections that cause acute colitis, often presenting with sudden onset of diarrhea, abdominal cramps, and fever. The specific pathogen can sometimes be suggested by the severity of symptoms, travel history, or exposure to contaminated food and water.
- Clostridioides difficile (C. diff) Colitis: A bacterial infection that can cause diarrhea, abdominal pain, and fever, especially after antibiotic use. It's a common cause of hospital-acquired diarrhea and should be considered in patients with recent antibiotic exposure.
- Do Not Miss Diagnoses
- Ischemic Colitis: A condition caused by reduced blood flow to the colon, which can lead to severe abdominal pain, bloody diarrhea, and potentially life-threatening complications if not promptly treated. Although less common, its potential for severe outcomes makes it crucial not to miss.
- Toxic Megacolon: A life-threatening complication of colitis characterized by a very inflated colon, which can occur in the context of severe inflammatory bowel disease or infectious colitis. It requires immediate medical attention to prevent perforation and sepsis.
- Amoebic Colitis: Caused by the parasite Entamoeba histolytica, it can present with bloody diarrhea, abdominal pain, and weight loss, similar to inflammatory bowel disease. Travel history to endemic areas or exposure to contaminated water can provide clues.
- Rare Diagnoses
- Microscopic Colitis: A type of colitis characterized by inflammation that can only be seen under a microscope, often presenting with chronic, watery diarrhea. It's more common in older adults and those with a history of certain medications or autoimmune diseases.
- Eosinophilic Colitis: A rare condition characterized by the presence of eosinophils in the colonic mucosa, which can be associated with food allergies, parasitic infections, or systemic diseases. Symptoms can include abdominal pain, diarrhea, and weight loss.
- Radiation Colitis: Inflammation of the colon due to radiation therapy, typically for pelvic malignancies. Symptoms can range from mild diarrhea to severe rectal bleeding and strictures, depending on the dose and duration of radiation exposure.
Each diagnosis has distinct features and risk factors that can guide the differential diagnosis. A thorough history, physical examination, laboratory tests, and sometimes endoscopic evaluation are necessary to determine the underlying cause of colitis.