What is the definition or description of: gluten insensitivity?

Gluten sensitivity: Celiac sprue. I think you mean gluten sensitity? Is an autoimmune disorder of the small intestine.Caused by a reaction to gliadin, a prolamin (gluten protein) found in wheat. Characteristic symptoms of pale, loose and greasy stool (steatorrhoea), and weight loss or failure to gain weight (in young children).

Intolerance or more?: Gluten intolerance (about 10% of people) may cause bloating, diarrhea, nonspecific complaints. Celiac disease, among its many manifestations may result in diarrhea. In the latter, exposure of intestine to gluten causes inflammation of affected gut lining, with a decrease in absorptive surface of that gut, & resulting malabsorption of food--best & most enduring fix being to avoid eating gluten.