 Gastrointestinal disorders are sometimes associated with aphthous @-@ like stomatitis , e.g. most commonly Celiac disease , but also inflammatory bowel disease such as Crohn 's disease or ulcerative colitis . The link between gastrointestinal disorders and aphthous stomatitis is probably related to nutritional deficiencies caused by malabsorption . Less than 5 % of people with RAS have Celiac disease , which usually presents with severe malnutrition , anemia , abdominal pain , diarrhea and <unk> ( inflammation of the tongue ) . Sometimes aphthous @-@ like ulcerations can be the only sign of celiac disease . Despite this association , a gluten @-@ free diet does not usually improve the oral ulceration . 
