Foods such as dairy products, fatty foods, sugar-free foods and gas-producing foods usually make diarrhea worse. Other foods that exacerbate diarrhea include alcohol, caffeine and carbonated beverages and unsafe foods.
Diarrhea often reduces the levels of the enzyme lactase, which is responsible for the digestion of the sugar found in dairy products. The reduction of lactase levels results in failure to properly digest the lactose, further aggravating diarrhea. Dairy products that contain lactose include butter, milk, ice cream and soft cheese.
Fatty foods, such as fried foods, greasy foods and foods covered in gravy, normally speed up intestinal contractions that further contributes to diarrhea. Certain sugar substitutes and artificial sweeteners have a laxative effect in particular people, which worsens diarrhea. These foods include diet soda, sugar-free candy, sugar-free gum and sugar substitutes for tea and coffee. Gassy foods such as beans, broccoli, onions, cabbage and certain fruits are known to increase intestinal gas which makes diarrhea worse.
Alcohol and caffeine drinks are not only diuretics but are also likely to cause intestinal irritation, leading to further diarrhea. Unsafe foods include foods that may have been incorrectly handled, foods that have been improperly stored and foods that have been out of the fridge for a long time. These foods increase the risk of intensifying diarrhea.