After dealing with a bout of diarrhea, you may not feel much like eating, but it may help you get better faster, according to a February 2014 article published in "American Family Physician." (see reference 1 under Feeding) Gastroenteritis, which is the medical term for loose, watery, frequent diarrhea that lasts for 14 days or less, is most commonly caused by a virus and requires very little medical intervention other than fluids for hydration (see reference 1 para 1 not bolded under Differential Diagnosis para under table 1). While doctors in the past may have recommended you slowly reintroduce food after a case of gastroenteritis, that's no longer necessary.
Eating After Gastroenteritis
Eating food as soon as you feel that you can may help prevent the infection from getting worse, according to the authors of the "American Family Physician" article, and may help you feel better faster (see reference 1 under Feeding). It also helps you get the nutrients you need for overall better health (see reference 1 under Feeding). While some doctors may recommend you limit your intake to foods such as bananas, rice, applesauce, tea and toast, also referred to as the BRAT diet, there's no evidence to support the efficacy of this type of diet when you have diarrhea (see reference 1 under Feeding).
Lactose and Diarrhea
You may want to limit your intake of milk and other lactose-containing foods when you have diarrhea. Although the research is limited, studies in children seem to show a decrease in the duration of diarrhea when lactose intake is limited, according to an October 2013 study published in "Cochrane Database of Systematic Reviews." (see reference 1 under Feeding, reference 2 under Effects of Intervention under Duration of diarrhoea not sure how to properly cite reference 2 in text).