Differential Diagnosis for 3 Weeks of Diarrhea in a 43-Year-Old Female
Single Most Likely Diagnosis
- Irritable Bowel Syndrome (IBS): Given the duration of symptoms, IBS is a common cause of chronic diarrhea in adults, especially in the absence of other alarming symptoms like blood in stool, significant weight loss, or fever.
Other Likely Diagnoses
- Infectious Gastroenteritis: Although the duration is a bit long for typical viral or bacterial gastroenteritis, some infections (like giardiasis) can cause prolonged diarrhea.
- Lactose Intolerance or Other Food Intolerances: These conditions can cause chronic diarrhea, especially if the patient has recently increased their intake of lactose-containing products or other potentially irritating foods.
- Medication-Induced Diarrhea: Various medications, including antibiotics, antacids, and laxatives, can cause diarrhea as a side effect.
Do Not Miss Diagnoses
- Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can present with chronic diarrhea and are crucial to diagnose early due to their potential for complications and the need for specific management.
- Celiac Disease: An autoimmune reaction to gluten that can cause chronic diarrhea, malabsorption, and other systemic symptoms. It's essential to diagnose due to the availability of an effective treatment (gluten-free diet).
- Colorectal Cancer: Although less common in this age group, it's a critical diagnosis not to miss, especially if there are other symptoms like weight loss, blood in stool, or a family history of colorectal cancer.
- Thyroid Disorders: Hyperthyroidism can cause chronic diarrhea among other symptoms, and it's essential to diagnose and treat due to its potential impact on the heart and other systems.
Rare Diagnoses
- Microscopic Colitis: A condition characterized by chronic, watery diarrhea, often without other symptoms. It's more common in older adults but can occur in any age group.
- Whipple's Disease: A rare, systemic bacterial infection that can cause chronic diarrhea, weight loss, and malabsorption, among other symptoms.
- Short Bowel Syndrome: Typically occurs after a significant resection of the small intestine, leading to malabsorption and chronic diarrhea. It's rare but important to consider in patients with a history of intestinal surgery.