Irritable Bowel Syndrome (IBS): This is a common condition characterized by abdominal pain and changes in bowel movements, which can include diarrhea after eating due to food sensitivities or intolerances.

Lactose Intolerance: A condition where the body is unable to digest lactose, a sugar found in milk, leading to diarrhea after consuming dairy products.
Food Poisoning: Consuming contaminated or spoiled food can lead to diarrhea, often accompanied by other symptoms like vomiting and abdominal cramps.
Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can cause chronic diarrhea, which may worsen after eating due to inflammation in the digestive tract.
Gastroesophageal Reflux Disease (GERD): Although primarily associated with heartburn, some individuals with GERD may experience diarrhea, possibly due to the reflux of stomach contents into the esophagus affecting bowel habits.

Celiac Disease: An autoimmune disorder where the ingestion of gluten leads to damage in the small intestine, causing diarrhea among other symptoms. Missing this diagnosis can lead to malnutrition and other complications.
Giardiasis: An infection caused by the Giardia parasite, which can lead to severe diarrhea and dehydration if not treated promptly.
Clostridioides difficile (C. diff) Infection: A bacterial infection that can cause severe diarrhea and colitis, especially after antibiotic use. It's crucial to diagnose and treat C. diff infections to prevent severe complications.

Short Bowel Syndrome: A condition where a significant portion of the small intestine is missing or not functioning, leading to malabsorption and chronic diarrhea.
Whipple's Disease: A rare, systemic bacterial infection that can cause malabsorption, diarrhea, and weight loss, among other symptoms.
Eosinophilic Gastroenteritis: A condition characterized by the presence of eosinophils in the gastrointestinal tract, leading to inflammation and symptoms like diarrhea, which can be triggered by food allergies or sensitivities.