Diverticulitis is a medical condition caused by diverticula, the plural of which is diverticuli. Diverticula are pouches in the wall of the large intestine or colon where Items such as hair, food, and bacteria accumulate. They can become infected and inflamed, leading to diverticulitis. Diverticulitis most commonly affects people over 50 years old, but can occur at any age. Acid reflux involves problems with the lower part of the gastrointestinal tract (esophagus and stomach). The key difference between these conditions is that diverticular disease typically affects only one collections (diverticular), while acid reflux can involve multiple collections.