Because this medical condition results in inflammation of the lining of your stomach, there are a number of symptoms that are associated with duodenitis. How intense these symptoms are varies from person to person. You may experience these symptoms on a daily basis or just every so often. These common symptoms at any time can become serious symptoms and may need medical attention. Some of the common symptoms of duodenitis may include:
1. Pain and discomfort in the abdomen
2. Abdominal bloating
3. Loss of appetite
4. Flatulence
5. Nausea and vomiting
6. Severe abdominal pain
7. Blood in stool
8. Gas along with excessive belching
9. Bleeding from the intestine

There are cases where this can be a life-threatening situation and if this happens you need to get immediate medical attention. These symptoms can include:
1. Stool that is bloody. The blood may appear to be black, tarry, or red in texture.
2. Abdominal pain that is severe
3. Vomiting blood