Why does your stomach hurt?
1. Stomach Flu (Acute Gastroenteritis)
One of the most common causes of sudden stomach pain is what many people call the “stomach flu.” The medical term is acute gastroenteritis, which simply means inflammation of the stomach and intestines caused by an infection.
What causes it?
- Viruses (like norovirus or rotavirus) are the most common cause worldwide.
- Bacteria (such as Salmonella or Campylobacter) can also cause infection, often through contaminated food.
Common symptoms:
- Cramping abdominal pain
- Nausea and vomiting
- Diarrhea
- Mild fever
Viral infections usually cause watery diarrhea and improve within a few days. Bacterial infections may feel more intense and sometimes cause higher fever or blood in the stool.
What helps?
Most cases go away on their own with rest and hydration. The biggest risk is dehydration, especially in children and older adults.
2. Celiac disease
If stomach pain keeps coming back or becomes long-term, one possible cause is celiac disease. This condition affects about 1 in 100 people worldwide.
Celiac disease is an autoimmune disorder. This means the immune system mistakenly attacks the body when gluten (a protein found in wheat, barley, and rye) is eaten.
Common symptoms:
- Ongoing stomach pain
- Bloating and excess gas
- Chronic diarrhea
- Fatigue
- Weight loss
Over time, untreated celiac disease damages the lining of the small intestine, making it harder to absorb nutrients properly. This can lead to anemia, weak bones, and other complications.
3. Infections and conditions that look similar
Several other conditions can cause symptoms that feel very similar to stomach flu or celiac disease.
Giardiasis
A parasite that infects the intestines. It can cause long-lasting diarrhea, bloating, and abdominal pain.
Helicobacter pylori (H. pylori)
This bacterium infects the stomach lining and can cause gastritis (stomach inflammation), indigestion, burning pain, and in some cases ulcers.
Irritable bowel syndrome (IBS)
IBS is a common functional gut disorder. That means the gut looks normal on medical tests but doesn’t function properly. Symptoms include:
- Recurrent abdominal pain
- Bloating
- Diarrhea, constipation, or both
Inflammatory bowel disease (IBD)
Unlike IBS, IBD involves real inflammation and damage in the intestines. It includes conditions like Crohn’s disease and ulcerative colitis. Symptoms often include:
- Persistent pain
- Chronic diarrhea
- Weight loss
- Fatigue
When should you worry?
Many stomach aches improve with rest, fluids, and time. However, you should seek medical advice if you notice:
- Pain that lasts more than a few days
- Unexplained weight loss
- Blood in your stool
- Ongoing diarrhea
- Severe or worsening pain
These could signal something more serious that needs medical evaluation.
The bottom line
Stomach pain can have many causes, from short-term infections to chronic conditions like celiac disease or inflammatory bowel disease. The key difference is duration and severity.
If the pain is brief and mild, it is often harmless. But if it keeps coming back, worsens, or is accompanied by other concerning symptoms, it’s important to investigate further. Understanding the common causes helps you know when to rest and when to seek help.
