Constant Indigestion and Gas: 8 Causes Explained.

Our content is not intended nor recommended as a substitute for medical advice by your doctor. Use for informational purposes only.

Constant indigestion is often a sign of upper gastrointestinal diseases such as chronic gastritis or GERD. However, a large subset may experience constant indigestion and gas due to functional disorders or a destructive lifestyle.

1. Bad Diet habits.

You are not alone; Dyspepsia (indigestion) is a widespread condition. One study estimated that about 38% of people experience indigestion (dyspepsia).

38% is a significant number. However, indigestion doesn’t always mean a disease. , You may experience constant indigestion due to a destructive lifestyle and dietary habits.

Continuing faulty diet and lifestyle habits lead to constant indigestion and gas.

Your diet choices make the difference:

Certain types of food cause gas and indigestion (dyspepsia) more than others. Our digestive system is not wired to digest every kind of food on our planet.

Some food cause gas and indigestion when you consume them constantly or in excess. And you don’t need to have any disease.

The complete list of gas-producing foods is in the table below. Therefore, when you constantly consume a large amount of one or more of the below table, You will experience constant digestion and gas.

1. Milk and dairy products– milk,
– ice cream,
– and sometimes, cheese and yogurt.
2. Vegetables– Broccoli,
– cauliflower,
– Brussel sprouts,
– onions,
– leeks,
– parsnips,
– celery,
– radishes,
– asparagus,
– cabbage,
– kohlrabi,
– cucumber,
– potatoes,
– turnips,
– and rutabaga.
3. Fruits– Prunes,
– apricots,
– apples,
– pears,
– peaches,
– raisins,
– bananas
4. Whole grains-wheat,
– oats,
– bagels,
– wheat germ,
– pretzels,
– bran/bran cereal
5. Legumes– Beans,
– peas,
– baked beans,
– soybeans,
– lima beans
6. FatsFried and high-fat foods.
7. Drinks– Carbonated beverages,
– beer,
– carbonated medications
8. Others– chewing gum,
– artificial sweeteners

2. Functional dyspepsia.

Functional dyspepsia is a widespread condition affecting more than 10% of people(reference). It affects women more than men.

Functional dyspepsia is one of the most common causes of constant indigestion. The exact cause is still unknown. It


We diagnose functional dyspepsia (FD) based on clinical symptoms. No specific test or imaging technique can diagnose the condition.

Laboratory tests, imaging techniques, and endoscopy exclude severe to exclude conditions similar to FD.

Functional dyspepsia causes constant indigestion and fullness. The most famous criteria of diagnosis of functional dyspepsia are the ROME IV criteria (reference):

Functional Dyspepsia ROME IV Criteria.

1. One or more of the following:
a. Bothersome postprandial fullness
b. Bothersome early satiation
c. Bothersome epigastric pain
d. Bothersome epigastric burning
2. AND
No evidence of structural disease (including at upper endoscopy) that is likely to explain the symptoms
* The above criteria must be fulfilled for the last three months
* symptom onset at least six months before diagnosis.

The symptoms of functional dyspepsia are different from occasional indigestion due to food. With functional dyspepsia, The symptoms are severe enough to interfere with your eating and daily activities.

3. Food intolerance & allergy.

Food intolerance is difficulty digesting certain types of food. It is a widespread condition affecting up to 20% of people (reference)

With food intolerance, Your digestive system is unable to break down and absorb the food. As a result, offending foods cause gas, nausea, and constant indigestion every time you eat them.

The most widespread form of food intolerance is lactose intolerance. Lactose is a sugar found in milk and dairy products.


  • Constant indigestion
  • Bloating sensation with or without visible distension of your abdomen.
  • Nausea and/or vomiting.
  • Colics and gurgling in the upper and/or lower abdomen.
  • Diarrhea.
  • Visible distension in the abdomen.
  • Abdominal pain.

Food allergy is a less common type of food reaction. It is an immune reaction to food that can lead to food intolerance symptoms (digestive symptoms) and allergic symptoms (such as skin hives and lip swelling).

Both food intolerance and food allergy can be constant indigestion.

The differences, symptoms, and common types are in the table below.

Food intoleranceFood allergy
Affects 15-20% of the populationAffects nearly 2-5% of adults
Indigestion of certain types of food (not immune-mediated allergy).An immune-mediated reaction to certain foods or food components.
Causes “recurrent acute” or “chronic” attacks of diarrhea, constant indigestion, and bloating.Usually causes acute attacks related to the ingestion of offending food.
Intestinal symptoms: diarrhea, extensive gas, bloating, distension (looking pregnant), and abdominal pain with constant indigestion.Intestinal symptoms are the same.
No extraintestinal symptomsExtraintestinal symptoms like rashes, urticaria, swollen lips or face, or severe life-threatening allergic reactions.
The severity of your symptoms is proportional to the amount you eat from the offending food.Even trace amounts of the offending food can produce severe symptoms.

Common offending foods:

  • Lactose intolerance (dairy products).
  • Fructose malabsorption.
  • Alcoholointolerance.
  • FODMAP intolerance (as with People with IBS).

Common offending foods: (examples)

  • Raw meat, seafood.
  • Nuts, peanut
  • Mustard.
  • Rice
  • Some vegetables and fruits

4. Chronic gastritis and Peptic ulcer disease.

Chronic gastritis, stomach ulcers, and duodenal ulcers cause constant epigastric pain and indigestion. In addition, chronic gastritis and peptic ulcer disease cause inflammation and damage to the lining of your stomach.



  • Drug-induced gastritis and PUD: most commonly, Nonsteroidal antiinflammatory drugs as ibuprofen and diclofenac.
  • H. Pylori infection.
  • Food: spicy foods, caffeine, alcoholo, fats, and acidic foods.
  • Less frequent causes of gastritis include immune-mediated gastritis, bile reflux, iron supplements, Crohn’s disease, and autoimmune diseases.


  • Pain in the epigastric area (upper middle part of your abdomen).
  • The pain is burning, aching, or gnawing in nature.
  • With chronic gastritis and stomach ulcers, the pain starts shortly after eating.
  • With duodenal ulcers, the pain is relieved by eating!
  • Constant indigestion.
  • Nausea, sometimes vomiting after eating.
  • Fullness or tight band sensation in the upper abdomen or the chest (below breasts).
  • Chronic gastritis usually follows an intermittent course with the recurrence of symptoms for months and years.
  • With peptic ulcer disease, the symptoms are the same but more extreme.
  • PUD can cause vomiting of blood (hematemesis) or passage of dark blackish stool (melena) when it bleeds.

5. Gastroparesis.

Gastroparesis is a decreased motility of your stomach. Slowing down of the stomach motility produce symptoms similar to Functional dyspepsia (constant indigestion and fullness in the upper stomach area).

The difference between gastroparesis and functional dyspepsia is:

  • Nausea, and abdominal pain is more common with functional dyspepsia than gastroparesis.
  • Vomiting is more prevalent with gastroparesis than functional dyspepsia.

Vomiting of undigested food eaten a few hours earlier can occur with gastroparesis. Also, in severe cases, loss of appetite, weight loss, and malnutrition can occur.

The most common cause of gastroparesis is diabetes mellitus. As diabetes may cause damage to the nerves supplying the stomach (vagus nerve).

Other causes and risk factors (ref):

  • Abdominal or esophageal surgery.
  • Infection, stomach viruses.
  • Certain medications such as pain medications.
  • Nervous system diseases as Parkinson’s disease and multiple sclerosis.
  • Hypothyroidism (underactive thyroid).
  • Scleroderma (a connective tissue disease).

Learn more about gastroparesis HERE.

6. GERD.

Gastroesophageal reflux disease (GERD) or chronic acid reflux is also a cause of constant indigestion. Indigestion is accompanied by two symptoms specific to GERD (heartburn and regurgitation).


  • Heartburn: A burning sensation in your chest and the upper stomach area. Heartburn typically increases when you lie down. That’s why stomach pain may be worse at night and in the early morning.
  • Regurgitation of bitter fluid or food particles into the throat.
  • Difficulty swallowing (dysphagia).
  • Pain during swallowing (odynophagia).
  • Bleching (eructation).
  • Constant indigestion (dyspepsia).
  • Nausea.
  • Vomiting occurs in severe cases.
  • A clinically significant GERD is defined as the occurrence of two or more attacks per week of night chest and stomach pain with regurgitation.

7. Irritable bowel syndrome

Irritable bowel syndrome is another prevalent FUNCTIONAL gut disease. It affects 10-15% of people worldwide.

A functional bowel disease means that the bowels appear normal, but their function is disturbed.

Interestingly, Only 40% of people who match the diagnosis of IBS have a formal diagnosis (reference). This leaves 60% of people NOT knowing that their symptoms are IBS. Your feeling of constant indigestion can simply be IBS.

According to the ROME IV criteria for IBS diagnosis, IBS is considered when the following symptoms exist:

  • Recurrent abdominal pain at least one day per week for the past three months.
  • The symptom onset is at least six months.
  • The abdominal pain is associated with at least 2 of the following:
  • 1- Defecation: abdominal pain either improve or worsens with defecation.
  • 2- Change in stool frequency: The onset of abdominal pain is associated with more frequent or less frequent bowel movements.
  • 3- change in stool form: the onset of pain is associated with harder or looser stool.

IBS has four subtypes, IBS with predominant diarrhea, constipation, Mixed IBS, and Unspecified IBS.

Consult your doctor if you have constant indigestion and prolonged symptoms consistent with IBS.

Learn more about how is IBS diagnosed?

8. Chronic pancreatitis.

Pancreatitis pain is often located in the upper-middle stomach area (above the belly button). The pancreatic pain is often severe with acute pancreatitis.

However, in cases of chronic pancreatitis, the pain is less severe and may be perceived as constant indigestion of fatty food and diarrhea.

Chronic pancreatitis is a state of chronic inflammation and destruction of the pancreatic cells. As a result, your pancreas is responsible for the secretion of digestive enzymes.

When its tissues become destructed, It leads to fat malabsorption, chronic diarrhea, and constant indigestion.

Symptoms of chronic pancreatitis:

  • Pain above the belly button in the middle of the stomach (less severe than acute pancreatitis pain).
  • The pain often radiates to the back.
  • Constant indigestion and bloating.
  • Recurrent diarrhea, particularly after eating fatty foods.
  • The stool is yellowish or grey, with an oily consistency.
  • Weight loss.
  • Occasional nausea or vomiting.
  • Some patients are asymptomatic.

Does Pancreatitis Cause Gas & Bloating?

9. Medications.

Dyspepsia or constant indigestion can be a result of a medication you take. Whether you take a drug for a temporary period or a lifetime, both can cause constant indigestion.

Revise your list of current medications for any of the below drugs.

If you are taking one or more of the medicines below, It may or may not be the cause of your system. So, don’t stop your medications without permission from your doctor.

Common medications that cause indigestion:

  • Potassium supplements,
  • Digitalis (for heart diseases).
  • Oral Iron supplements (in general tonics and the treatment of anemia.
  • Theophylline (used in patients with chest disease like bronchial asthma).
  • Oral antibiotics (especially ampicillin and erythromycin).
  • Nonsteroidal anti-inflammatory drugs (NSAIDs).
  • Glucocorticoids (corticosteroids used for the treatment of autoimmune diseases and others).
  • Niacin.
  • Gemfibrozil.
  • Narcotics.
  • Colchicine.
  • Quinidine.
  • Estrogens (in oral contraceptive pills).
  • Levodopa (for treatment of neurological disorders such as Parkinsonism).

10. Others.

  • Pregnancy.
  • Stomach or esophageal cancer.
  • Thyroid disease.
  • Celiac disease.
  • SIBO.
  • Gallbladder diseases.
  • Enlarged spleen.
  • Functional abdominal bloating.
  • Chronic abdominal wall pain.

When to see a doctor for constant indigestion?

  • Unexplained weight loss.
  • Persistent bothersome symptoms with no precise diagnosis or explanation.
  • Difficulty swallowing (dysphagia).
  • Painful swallowing (odynophagia).
  • Unexplained iron deficiency anemia.
  • Persistent or recurrent vomiting.
  • Enlarged lymph nodes in the neck, axilla, or thigh.
  • Family history of stomach, esophageal, or colorectal cancer.
  • Passage of blood or mucus in stool.