Differential Diagnosis for Daily Loose Stools
Single Most Likely Diagnosis
- Irritable Bowel Syndrome (IBS): This is a common condition characterized by chronic abdominal pain, bloating, and alteration of bowel habits, which can include daily loose stools. The diagnosis is often made based on symptom criteria (Rome IV) in the absence of other explanatory conditions.
Other Likely Diagnoses
- Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can cause chronic diarrhea due to inflammation in the gastrointestinal tract. Blood in the stool, weight loss, and abdominal pain are common accompanying symptoms.
- Gastroesophageal Reflux Disease (GERD) and Functional Dyspepsia: While primarily associated with upper GI symptoms, some patients may experience diarrhea, possibly due to altered gut motility or sensitivity.
- Lactose Intolerance or Other Food Intolerances: Inability to digest certain foods can lead to daily loose stools, bloating, and gas. Common culprits include lactose, fructose, and gluten (in those with celiac disease or non-celiac gluten sensitivity).
- Small Intestine Bacterial Overgrowth (SIBO): An overgrowth of bacteria in the small intestine can lead to bloating, gas, and diarrhea due to the malabsorption of nutrients.
Do Not Miss Diagnoses
- Infectious Diarrhea (e.g., Giardiasis, Clostridioides difficile): Certain infections can cause chronic diarrhea. It's crucial to identify these, as they require specific treatments that can significantly improve symptoms and prevent complications.
- Thyroid Disorders (Hyperthyroidism): An overactive thyroid gland can cause increased bowel movements, among other symptoms like weight loss, palpitations, and heat intolerance.
- Diabetic Diarrhea: Some people with diabetes experience diarrhea due to autonomic neuropathy affecting the gut or due to malabsorption.
- Medication-Induced Diarrhea: Various medications, including antibiotics, antacids, and blood pressure medications, can cause diarrhea as a side effect.
Rare Diagnoses
- Short Bowel Syndrome: A condition where a large portion of the small intestine is missing or not functioning, leading to malabsorption and chronic diarrhea.
- VIPoma: A rare tumor that produces vasoactive intestinal peptide (VIP), leading to severe, chronic diarrhea (often >1 liter/day), hypokalemia, and achlorhydria.
- Zollinger-Ellison Syndrome: A rare disorder characterized by excessive gastric acid production due to a gastrin-producing tumor, leading to diarrhea among other symptoms.
- Carbohydrate Malabsorption (e.g., Sucrose Isomaltase Deficiency): Rare genetic disorders that affect the body's ability to digest certain carbohydrates, leading to diarrhea after consuming these substances.