Final answer:
Lethal White Syndrome in foals is associated with intestinal obstruction, which is a severe condition leading to colic and inability to move food through the intestines.
Step-by-step explanation:
The gastrointestinal issue associated with Lethal White Syndrome in foals is intestinal obstruction. Lethal White Syndrome is a genetic disorder typically affecting American Paint Horses, where foals are born with a dysfunctional enteric nervous system. This leads to an inability of the intestines to move food properly, causing severe colic and eventual intestinal obstruction. The affected foals usually show signs such as abdominal pain, discomfort, and distention. Unfortunately, due to the severity of the condition, most foals with Lethal White Syndrome die within the first few days of life unless euthanized for humane reasons. It is important to note that although symptoms such as diarrhea, nausea, and vomiting may be present in various gastrointestinal conditions, intestinal obstruction is the specific issue connected to Lethal White Syndrome.