Irritable Bowel Syndrome (IBS): This is often the most common cause of intermittent diarrhea, characterized by abdominal pain, changes in bowel habits, and no identifiable cause. The intermittent nature of the symptoms aligns with the typical presentation of IBS.

Infectious Gastroenteritis: Viral or bacterial infections can cause episodes of diarrhea. The intermittent pattern could reflect repeated exposures or a persistent infection.
Food Intolerances: Lactose intolerance, fructose malabsorption, or gluten sensitivity (in the form of non-celiac gluten sensitivity) can lead to intermittent diarrhea based on dietary intake.
Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can present with intermittent diarrhea, although they often have additional symptoms like blood in stool and significant abdominal pain.

Giardiasis: An infection caused by the Giardia parasite, which can lead to intermittent diarrhea. It's crucial to consider this diagnosis, especially in individuals with a history of travel or exposure to contaminated water.
Celiac Disease: An autoimmune reaction to gluten that can cause diarrhea among other symptoms. Missing this diagnosis can lead to malabsorption and long-term health issues.
Colorectal Cancer: Although less common, new-onset intermittent diarrhea can be a symptom of colorectal cancer, especially in older adults. It's critical to rule out this possibility, particularly if accompanied by other alarming symptoms like weight loss or blood in stool.

Microscopic Colitis: A condition characterized by inflammation of the colon that can cause chronic or intermittent watery diarrhea. It's often diagnosed in older adults and can be challenging to detect without a colonoscopy.
Bile Acid Diarrhea: Occurs when the body produces too much bile acid, leading to diarrhea. This condition can be primary (idiopathic) or secondary to other diseases like Crohn's disease or after certain surgeries.
Whipple's Disease: A rare, systemic bacterial infection that can cause diarrhea among a wide range of other symptoms. It's essential to consider in patients with unexplained, prolonged diarrhea and systemic symptoms like weight loss and arthralgias.