colitis symptoms

Question
I recently rescued a 10 year old dog that may have colitis.  His symptoms include very loose stools, and old records show he was treated off and on with medication.  I would like to know how to determine if this condition is due to stress or is it physiological?  Are the loose stools stress induced?  Any information would be greatly appreciated.

Answer
It could be due to stress, diet change or food allergy, intestinal parasites, inflammatory bowel disease, viral or bacterial infection....I would recommend an easy to digest, all-natural diet (Flint River Ranch, Innova, CA Natural, Nutro Natural, Verus, Natural Balance) as well as supplementing his diet with digestive enzymes such as Prozyme and Probiotics such as acidophilus tablets or yogurt.  We often seen colitis when dogs are boarding or if they eat something they shouldn't.  Daily living conditions should not be stressul that would induce loose stools continuously.