Most people are occasionally plagued by digestive issues from eating too much or too fast, for example. However, there are certain stomach signs and symptoms that could signal a more serious problem.  

“I’ve seen many cases where patients have waited way too long before seeking medical attention,” says Dr. Christine Lee, a gastroenterologist at the Cleveland Clinic.

Here are symptoms you should never ignore and what they could mean:

1. Prolonged diarrhea. According to AARP, diarrhea can be a symptom of several conditions, from a food allergy to a bacterial infection. It can also be a warning sign of COVID-19, notes Dr. Brennan Spiegel, director of health services research for Cedars-Sinai Medical Center in Los Angeles. Studies reveal that half of COVID-19 patients suffer gastrointestinal (GI) symptoms. In fact, 15% to 20% of them have only GI symptoms. Don’t wait for a cough or shortness of breath to get tested for COVID-19, warns Spiegel. Prolonged diarrhea may also signal ulcerative colitis or irritable bowel syndrome (IBS).
2. Blood in your stool. While this is usually not a life-threatening condition, it could be a sign of colon cancer, especially for those over the age of 50. According to Fort HealthCare, of Fort Memorial Hospital in Wisconsin, you should see a doctor as soon as possible to schedule a colonoscopy. Other causes of bloody stool could be hemorrhoids, anal fissures, colon polyps or colitis.
3. Sudden stomach pain. If you have an onset of severe pain around the navel accompanied by nausea, fever and vomiting it may be caused be appendicitis, according to Reader's Digest. Go directly to the hospital.
4. Sudden pain below the navel. When the pain radiates to either side of the navel, it could be triggered by a urinary tract infection or pelvic inflammatory disease. If the pain is situated on the right side only below the navel, this could mean gallstones or gall bladder inflammation. See your doctor for diagnostic tests, say the experts at Reader’s Digest.
5. Difficulty swallowing. According to AARP, this could indicate esophageal cancer, especially in men over the age of 55. You may also have an infection or ulcer that’s making it hard for you to swallow, so it is important to consult with a gastroenterologist who can properly diagnose the cause. A growing number of people are being diagnosed with eosinophilic esophagitis (EOE), a chronic inflammatory disease that is a major cause of swallowing issues.
6. Unexplained weight loss. Lee says that most people tend to gain weight as they get older, but if you are losing weight unintentionally, this could be a red flag. Although this could be a symptom of cancer, studies show that weight loss could be also caused by celiac disease, inflammatory bowel disease or an overactive thyroid.  
7. Chronic or prolonged constipation. While almost everyone suffers occasional constipation, especially older adults, if prolonged constipation isn’t treated it could be painful and even deadly. “If it goes longer than seven days, I want to see you,” says Dr. Nicholas Anthony, a gastroenterologist at Atrium Health in Charlotte, N.C. Constipation can be caused by certain medications, a low-fiber diet, and medical conditions such as IBS, thyroid issues, diabetes, or rarely, colorectal cancer.
8. Swollen abdomen. Bloating after eating a big meal is common, but if the abdomen continues to feel and look distended after there has been plenty of time to digest, it could signal excess fluid or gas forming in your small intestine as the result of an obstruction, inflammation, bacterial overgrowth, or a gastrointestinal disease, says AARP.