Stomach bloating may refer to a sensation of fullness or pressure which typically occurs after eating, and/or excessive gas accumulation within the gastrointestinal tract. Typically these symptoms are associated with indigestion, however, there are various other causes of stomach bloating that may or may not be related to the gastrointestinal tract (gut).
Although the term bloating is sometimes used to refer to an enlarged abdomen, this is technically known as abdominal distension. With stomach bloating, there may be little or no enlargement of the abdomen. Common causes of a visible bulging or protrusion of the stomach may be due to fluid which causes abdominal swelling (ascites), feces (constipation), fat (abdominal fat/central obesity), fetus (pregnancy), flatus (gas accumulation).
Sensation of Fullness
A feeling of fullness or pressure in the stomach, abdominal area or under the left ribcage, is often described as stomach bloating especially if it follows eating or drinking. This sensation may be a result of gas accumulation or a vague stomach or abdominal fullness. It may be accompanied by nausea and vomiting.
The causes of this sensation of fullness or pressure in the stomach includes :
- Functional dyspepsia (non-ulcer dyspepsia)
- This is a syndrome of symptoms that typically start after eating when there is no diagnostic evidence of any other gastrointestinal disease.
- Inflammation of the lining of the stomach commonly due to H.pylori infection or use of NSAIDs. It can progress to a peptic ulcer.
- Peptic ulcer
- Ulceration in the lining of the esophagus, stomach or duodenum usually as a result of chronic gastritis.
- Infection of the stomach and duodenum causing nausea, vomiting, diarrhea and a fever.
- Hiatal hernia
- Protrusion of a portion of the stomach into the chest cavity through the diaphragmatic opening.
- Gastric outlet obstruction
- Delayed gastric emptying due to the conditions like pyloric stenosis, gastroparesis, polyps or a tumor. The causes are discussed further under Slow Stomach.
- Irritable bowel syndrome
- Functional bowel disorder that may affect gut motility and characterized by non-specific symptoms like a sensation of bloating. Excessive gas may also be contribute to stomach bloating.
- Post-operative inflammation of the stomach may cause a sensation of fullness. This feeling may be chronic in surgical resection (removal of a part of the stomach in the treatment of conditions like cancer) or bariatric (weight loss) surgery.
Stomach gas bloating or excessive gas within the bowels after eating a meal may be due to a number of factors, some of which are related to disease processes. Gas in the gut is produced as a result of air swallowing, gas intake in carbonated drinks, byproduct of chemical digestion and the action of bacteria in the gut. The symptoms associated with stomach bloating due to gas accumulation includes :
- Excessive belching
- Excessive flatulence
- Abdominal discomfort or pain
- Nausea and/or vomiting
- Changes in bowel movement
Stomach bloating may occur with no other symptoms apart from the abdominal distension. In most people who suffer with stomach bloating, the enlargement is visible anywhere between 20 or 30 minutes to an hour after eating. However, there are cases where eating leads to stomach bloating immediately after the meal.
The build up of gas in the gut may be due to a number of factors that are not related to any disease process (physiological, non-pathological).
- Air swallowing (aerophagia)
- Carbonated beverages
- Gassy foods
- Chemical digestion
- Normal intestinal flora (gut bacteria)
If one or more of these causes of stomach gas are exacerbated, the gas accumulation within the gut can increase substantially. The causes that may increase gas in the upper gut includes :
- H.pylori infection
- Infects the stomach and duodenum, increases gastric acid secretion and causes gastritis.
- Small intestine bacterial overgrowth
- Overgrowth of intestinal bacteria like Clostridium difficile increases consumption of food in the gut thereby producing gas.
- Food intolerance and malabsorption
- Intolerances to foods high in lactose (dairy) and gluten (wheat) and malabsorption of sugars likes fructose and sorbitol.
- The slow transit of food increases exposure to gastrointestinal bacteria and digestive enzymes (chemical digestion).
- Pancreatic exocrine insufficiency
- Diminished or absent pancreatic digestive enzymes due to conditions affecting its production or secretion.
- Biliary Stasis
- Reduced secretion of bile due to diminished production or obstruction in the bile duct (gallstones or tumor).
Stomach Bloating Immediately After Eating
Stomach bloating may at times occur immediately after a meal, within minutes or in rare cases while eating. The most common cause for this is due to air swallowing (aerophagia) or consuming carbonated drinks. In both these cases, it can be avoided to a large extent.
Stomach bloating immediately after a meal is also seen in irritable bowel syndrome. The exact cause for this is unknown but there is no significant increase in gas within the alimentary tract. Non-ulcer dyspepsia or functional dyspepsia is due to unknown causes, but like IBS which is another functional gut disorder, stomach bloating may occur for no known reason after a meal.
Other causes may include :
Stomach Bloating Shortly After Meals
Most cases of stomach bloating due to pathology beyond within the small intestine, pancreas, gallbladder or bile ducts, do not occur immediately after meals. Patients may report a sensation of bloating, which refers to the feeling of fullness, immediately after eating but visible distension may only be seen 20 minutes or more after the meal.
This may be due to consuming ‘gassy foods’. A list of these foods are available under Gassy Stomach. It rarely causes bloating immediately after eating as these foods have to be partially digested before causing excessive gas.
This includes :
- Helicobacter pylori
- Clostridium difficile
- Other microorganisms that cause infectious gastroenteritis
- Food poisoning (bacterial toxins)
- Food Intolerance and Malabsorption
- Lactose intolerance
- Gluten intolerance (celiac sprue)
- Fructose malabsorption
- Sorbitol malabsorption
- Other malabsorption syndromes
- Maldigestion (Digestive Problems)
- Pancreatic exocrine insufficiency (pancreatic digestive enzyme deficiency)
- Cholestasis (biliary stasis) – reduction or lack of bile due to gallstones, bile duct stones, hepatocellular or pre-hepatic disorders
- Hypochlorhydria or achlorhydria – low or no stomach acid
- Zollinger-Ellison syndrome
- Inflammatory bowel disease
- Gastrointestinal motility
- Dumping syndrome
- Delayed gastric emptying
- Blocked bowels
- Abdominal Examination. Medscape