<P> Common causes include Helicobacter pylori and NSAIDs . Less common causes include alcohol, cocaine, severe illness and Crohn disease, among others . </P> <P> Helicobacter pylori colonizes the stomachs of more than half of the world's population, and the infection continues to play a key role in the pathogenesis of a number of gastroduodenal diseases . Colonization of the gastric mucosa with Helicobacter pylori results in the development of chronic gastritis in infected individuals, and in a subset of patients chronic gastritis progresses to complications (e.g., ulcer disease, stomach cancers, some distinct extragastric disorders). However, over 80 percent of individuals infected with the bacterium are asymptomatic and it has been postulated that it may play an important role in the natural stomach ecology . </P> <P> Gastritis may also develop after major surgery or traumatic injury ("Cushing ulcer"), burns ("Curling ulcer"), or severe infections . Gastritis may also occur in those who have had weight loss surgery resulting in the banding or reconstruction of the digestive tract . </P> <P> Evidence does not support a role for specific foods including spicy foods and coffee in the development of peptic ulcers . People are usually advised to avoid foods that bother them . </P>

What are the key features of chronic gastritis