See below. In food intolerance, an individual is intolerant to one or more specific types of food. This can cause symptoms such as diarrhea, bloating, abdominal pain, or malabsorption. Diet elimination means systematically eliminating specific foods from the diet to see if symptoms improve. After several trials with different foods, symptoms may improve indicating that food is the offending agent.
Eliminate foods. You eliminate one food at a time for a couple of days to a week, to see if there is an effect on your symptoms. For example, someone with colitis, might eliminate milk and find that the diarrhea improves. That is an elimination diet. There are other foods in colitis that might help as well. But you have to eliminate them one at a time to find out.