Excessive flatulence can indicate stomach cancer, although it is an uncommon cause, according to Healthline. More common causes of excessive flatulence include lactose intolerance, irritable bowel syndrome, indigestion, gallstones and Crohn's disease. An E. coli, giardiasas, H. pylori or amebiasis infection may also cause gas.
Digestive disorders, including celiac disease, dumping syndrome, gastroparesis and peptic ulcer, may cause excessive gas, notes Mayo Clinic. Celiac disease is an immune-system response to eating gluten. Dumping syndrome usually occurs after surgery and results in food passing too quickly through the small bowel. The spontaneous movements of stomach muscles do not function normally in an individual with gastroparesis, and peptic ulcers are open sores in the upper portion of the small intestine, the esophagus and the stomach.
Stomach cancer in the early stages normally does not cause symptoms, although the individual may experience some minor upper abdominal discomfort, loss of appetite, discomfort swallowing and nausea, explains the Angeles Clinic and Research Institute. In addition to excessive gas, other symptoms of stomach cancer include blood in stools and vomit, bad breath, anemia, and an abdomen that feels full and painful, even if the individual has not eaten.
As a single symptom, intestinal gas is usually not a sign of a serious condition, advises Mayo Clinic. However, individuals with persistent or severe flatulence should consult a doctor to rule out serious causes. Additional accompanying symptoms that mandate a doctor's attention include unintentional weight loss, heartburn, diarrhea, constipation and vomiting.