Differential Diagnosis for Chronic Diarrhea
Single Most Likely Diagnosis
- Irritable Bowel Syndrome (IBS): This is often considered the most likely diagnosis for chronic diarrhea due to its high prevalence and the fact that it can present with a variety of gastrointestinal symptoms, including chronic diarrhea, without an identifiable cause.
Other Likely Diagnoses
- Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can cause chronic diarrhea, along with other symptoms such as abdominal pain and weight loss.
- Lactose Intolerance: The inability to digest lactose, a sugar found in milk and other dairy products, can lead to chronic diarrhea in some individuals.
- Gastroesophageal Reflux Disease (GERD): Although more commonly associated with heartburn, GERD can also cause chronic diarrhea in some cases.
- Small Intestine Bacterial Overgrowth (SIBO): An overgrowth of bacteria in the small intestine can lead to chronic diarrhea, bloating, and abdominal pain.
Do Not Miss Diagnoses
- Colon Cancer: While less common, colon cancer can present with chronic diarrhea, especially in older adults, making it crucial not to miss this diagnosis.
- Celiac Disease: An autoimmune reaction to gluten can cause chronic diarrhea, malabsorption, and other systemic symptoms.
- Thyrotoxicosis: Hyperthyroidism can cause chronic diarrhea due to the increased metabolic rate.
- Whipple's Disease: A rare bacterial infection that can cause chronic diarrhea, weight loss, and malabsorption.
Rare Diagnoses
- Microscopic Colitis: A condition characterized by inflammation of the colon lining, which can cause chronic diarrhea.
- Eosinophilic Gastroenteritis: A rare condition involving eosinophilic infiltration of the gastrointestinal tract, leading to chronic diarrhea and other symptoms.
- VIPoma: A rare pancreatic tumor that secretes vasoactive intestinal peptide (VIP), causing chronic diarrhea, hypokalemia, and achlorhydria.
- Carcinoid Syndrome: A rare condition caused by a neuroendocrine tumor secreting serotonin, leading to chronic diarrhea, flushing, and wheezing.