Although mainly expressing in the gastrointestinal (GI) tract, a digestive disorder may produce symptoms outside of the digestive system, or in a portion of this system far away from the primary disease site. Several GI conditions can give rise to symptoms in the oral cavity, within tissues in or around the mouth. These could actually come about prior to intestinal signs or in conjunction with other indications, and could result from the disease itself, or be produced by a secondary effect such as ineffective nutrient assimilation by a compromised bowel (malabsorption).

Interestingly, some oral conditions may even lead to a gastrointestinal disease. For example, in a retrospective look at the health of 52,000 male doctors, researchers observed that men with a history of gum disease had a 63% greater risk of developing pancreatic cancer relative to men without periodontal disease. Persistent gum disease results in accumulation of high levels of harmful bacteria in the mouth and gut, which could be cancer causing.

Oral symptoms, while not enough to provide a definitive diagnosis on their own, can be a significant factor in pointing a clinician toward a positive GI diagnosis and prompt them to investigate the GI tract further for the possible source of distress. In some cases, oral signs may appear in the absence of obvious intestinal abnormalities.


Inflammatory Bowel Disease (IBD)

From 0.5-8% of Crohn’s disease patients experience oral lesions, characterized as small sites of inflammation, or granulomas. Additionally, the patient may develop swelling of the lips, gums, and oral tissues causing difficulty eating. Oral symptoms can be similar to lesions occurring elsewhere in the digestive tract, with a pattern of swelling, inflammation, ulcers, and fissures. If these signs are present, then patients are more likely to also have anal and esophageal lesions and experience other extra-intestinal disease manifestations. Usually symptoms appear in patients with already diagnosed disease and rarely precede involvement of the intestines. Treatment includes topical corticosteroids or even corticosteroid injections directly into the lesions. Systemic therapy has shown variable results.

Oral lesions are far less common in cases of ulcerative colitis. Again, these lesions usually present at the same time as intestinal lesions, and develop in the oral cavity, although not usually on the tongue. They are microscopically distinguished from oral Crohn’s disease lesions, and, unlike in Crohn’s disease, the severity of oral symptoms parallels overall disease severity. Symptoms normally respond to systemic treatment, topical corticosteroids, and dapsone, an antibacterial medication.


Acid Reflux

The primary oral manifestation of acid reflux, caused by conditions such as gastroesophageal reflux disease (GERD) and hiatus hernia, is erosion of tooth enamel. This occurs with the regurgitation of highly acidic stomach contents that increases the acidity of the mouth and dissolves tooth enamel.

The degree of enamel erosion aids a clinician in diagnosing the severity of GI disease. Erosion of enamel is irreversible, and in some cases may require restorative dental treatment.



Patients with jaundice, a condition causing yellowish discolouration resulting from increased bilirubin in the blood, may see the effects manifest in their oral tissues. The result is a yellowish tinge in the mouth, which is usually more pronounced on the lingual frenulum (underside of the tongue) and the soft palate. In children, whose enamel has not yet calcified, the discolouration may extend to the teeth themselves, causing a yellowish to greenish tinge. Individuals ingesting large amounts of vitamin A may also have pigmentation of the soft palate, so only a medical professional should determine the symptom cause.


Malabsorption Conditions

Generally, these conditions occur when proper bowel function is compromised, including a reduced ability to absorb essential nutrients. This state can result from disease, such as celiac or Crohn’s, or from medical procedures such as gastric bypass surgery or bowel resection. Oral symptoms vary with the specific missing micronutrient; however, the two most common examples are iron deficiency anemia and vitamin B12 malabsorption in pernicious anemia. In severe cases, the result is inflammation or infection of the tongue, leaving a sore, bald, red tongue. Ulcers or lesions can appear and a burning sensation may accompany or precede these signs. Other regions of the mouth may be less severely affected, and these symptoms often go unnoticed.



Knowing that a patient has any of the above oral conditions could be useful information for a physician when diagnosing someone who is also experiencing gastrointestinal difficulties. Therefore, it is important for patients to provide their doctors with a complete picture of all areas within the body that are not functioning properly, even if symptoms seem unrelated to the gastrointestinal tract.

First published in the Inside Tract® newsletter issue 165 – January/February 2008
1. Daley TD, et al. Oral manifestations of gastrointestinal diseases. Canadian Journal of Gastroenterology. 2007;21(4):241-244.
2. Casiglia JM, et al. Oral manifestations of systemic diseases. EMedicine Website. Last accessed on August 5, 2011.
3. Michaud DS, et al. A prospective study of periodontal disease and pancreatic cancer in US male health professionals. Journal of the National Cancer Institute. 2007;99:171-5.