Differential Diagnosis for Watery Diarrhea
Single Most Likely Diagnosis
- Viral Gastroenteritis: This is the most common cause of watery diarrhea, often due to norovirus or rotavirus, especially in outbreaks or in individuals with recent travel or exposure history. The symptoms typically include sudden onset of watery diarrhea, vomiting, and abdominal cramps.
Other Likely Diagnoses
- Bacterial Gastroenteritis: Caused by bacteria such as Escherichia coli, Salmonella, Shigella, and Campylobacter. These infections can lead to watery diarrhea and are often associated with food poisoning or contaminated water.
- Food Intolerance: Lactose intolerance, fructose malabsorption, and other dietary intolerances can cause watery diarrhea after consuming specific foods.
- Irritable Bowel Syndrome (IBS): Although IBS can cause a variety of symptoms, some patients may experience watery diarrhea, especially with the IBS-D subtype.
- Medication-Induced Diarrhea: Certain medications, such as antibiotics, laxatives, and antacids, can cause watery diarrhea as a side effect.
Do Not Miss Diagnoses
- Cholera: A severe infection caused by Vibrio cholerae, characterized by profuse watery diarrhea, which can lead to rapid dehydration and death if not promptly treated.
- Clostridioides difficile (C. diff) Infection: A bacterial infection that can cause severe, watery diarrhea, especially in individuals who have recently used antibiotics or have been hospitalized.
- Giardiasis: An intestinal infection caused by the parasite Giardia lamblia, which can lead to chronic watery diarrhea if not treated.
Rare Diagnoses
- Whipple's Disease: A rare, systemic bacterial infection caused by Tropheryma whipplei, which can lead to chronic diarrhea among other symptoms.
- Microscopic Colitis: A condition characterized by chronic, watery diarrhea, often without visible inflammation on endoscopy but with microscopic changes in the colon lining.
- VIPoma: A rare endocrine tumor that secretes vasoactive intestinal peptide (VIP), leading to a syndrome of watery diarrhea, hypokalemia, and achlorhydria (WDHA syndrome).
- Celiac Disease: An autoimmune disorder where the ingestion of gluten leads to damage in the small intestine, which can cause chronic diarrhea among other symptoms.