Worried that you have an ulcer? Ulcers can be very painful. Below are five of the most common symptoms of ulcers: burning or gnawing feeling in the stomach that comes and goes, pain that feels like it may be heartburn or indigestion, pain after eating, burning pain that wakes you up at night, and loss of appetite. If you have any of the above symptoms, you may be one of millions of people suffering from stomach ulcers. See your doctor today.