What are the Causes of Abdominal Bloating?

What is the difference between Abdominal Bloating, Distension, or Abdominal Swelling?
Abdominal bloating is a feeling of fullness or swelling and tightness in the abdomen (tummy) and is sometimes described as the feeling of an inflated balloon in the belly. It is usually due to excess gas or liquid. Generally, the feeling subsides once the gas passes out. Another term called abdominal distention also means swelling of the abdomen but there is an actual increase in abdominal girth when measured. Abdominal swelling is used as a description for both bloating or distension, however, a swelling may not reduce if it is due to a benign or malignant tumor inside the abdomen

Bloating is a common problem affecting 10-30% of people. The bloating-related symptoms are burping, abdominal pain, flatulence (passing of gas), and abdominal distension.

The bloating may occur due to the swallowing of air or due to the gases released during the process of food digestion. When the gas is not passed out by burping or flatulence, it can lead to bloating. The pain due to the retention of gas can be dull and mild to intense and sharp.

What are the Causes of Abdominal Bloating, distension, or Swelling?
Abdominal bloating, distension or Swelling can be due to:

Functional Gastrointestinal Disorders, where there is a problem in the function of the digestive tract
Organic Gastrointestinal Disorders, where there is a structural problem in the digestive tract, or
Non-Gastrointestinal Disease, where the problem arises outside the digestive tract
Some of the causes of abdominal bloating are listed below:

Diet: Certain foods like broccoli, beans, onions, cabbage, cauliflower, brussels sprouts, lettuce, apples, pears, peaches, milk, pulses, chewing gum, carbonated drinks, and whole grain foods can cause bloating. The patient may give a history of excessive intake of these foods. The bloating reduces if the specific food causing it is avoided.

Foods to Avoid During Abdominal Bloating

Lactose Intolerance: Lactose intolerance is the inability to digest lactose, a sugar present in milk and its products. It occurs when the small intestines fail to produce enough amounts of lactase, an enzyme that digests the lactose. The symptoms of lactose intolerance include bloating, pain, cramps in the belly, vomiting, and diarrhea following intake of milk and milk products. Avoiding lactose-containing foods is recommended to prevent discomfort.

Irritable Bowel Syndrome (IBS): Irritable bowel syndrome is a chronic functional gastrointestinal disorder. Patients with IBS may have abdominal pain, bloating, mucous in stool, and diarrhea or constipation. In patients with IBS, avoiding the foods that trigger the symptoms is recommended. Since there is a psychological aspect to IBS, patients may benefit from techniques to reduce stress.

Intestinal Obstruction: Intestinal obstruction is a condition where there is a blockage in the lumen of the intestines which prevents the flow of the intestinal contents. Causes of intestinal obstruction include roundworms, severe constipation, colon cancer, and intussusception (where one part of the intestine telescopes into another). The patient may present with pain in the abdomen, constipation, vomiting, abdominal distension, and bloating. Intestinal obstruction has to be managed immediately to prevent complications.

Gastroparesis: Gastroparesis is a disorder where the movement of food is slowed down or stopped from the stomach to the intestine. It occurs due to damage to the vagus nerve that supplies to stomach muscle and causes it to contract. Diabetes neuropathy affecting the vagus nerve is a common cause of gastroparesis. Bloating is present in these patients

Chronic Constipation: In patients with chronic constipation, bloating may be present due to the retention of stools in the large intestine, which gets fermented by bacteria to release gas. The patient usually gives a history of constipation.

Causes of Abdominal Bloating – Constipation.

Celiac Disease: Celiac disease is an autoimmune disease of the intestine with a genetic predisposition. Patients with celiac disease cannot digest gluten, a protein present in foods made of grains like wheat, barley, and rye. Consuming gluten causes various gastrointestinal symptoms including bloating. Patients should be advised of strict dietary restrictions on gluten.

Cirrhosis of the Liver: Cirrhosis is a condition where the function of the liver deteriorates due to chronic liver disease like alcoholism. Bloating is seen in these patients due to the accumulation of fluid in the abdomen, a condition called ascites. The patients usually give a history of underlying liver disease.

Congestive Heart Failure: Congestive heart failure is a condition where the pumping action of the heart is lesser than normal. Bloating in these patients is due to the accumulation of fluid in the abdomen, which may occur at a later stage. The patient shows other signs of heart failure like swelling of feet and shortness of breath.

Pancreatic Insufficiency: The pancreas secretes digestive enzymes. So in patients with pancreatic insufficiency, the enzymes produced are not sufficient for the digestion of the food. The patients present with pain in the abdomen, bloating, and oily stools.

Pancreatic Insufficiency Can Cause Abdominal Bloating
Kidney Diseases: Kidney diseases can lead to kidney failure. Kidney failure causes fluid retention in the abdomen which can cause bloating.

Pregnancy: Increased levels of progesterone during the early pregnancy leads to the relaxation of the intestine which in turn can result in bloating.

Hypothyroidism: A decreased level of thyroid hormones is called hypothyroidism. In patients with hypothyroidism, constipation and bloating are common due to the slow gut movement. Hypothyroidism is diagnosed through blood tests.

Babies and Bloating: Newborns and infants often have a bloating problem since they swallow a lot of air while suckling. Proper feeding techniques and burping are necessary to prevent gas in babies.

Premenstrual Syndrome: Premenstrual syndrome is experienced due to hormonal variations for 1-2 weeks just before menstruation. The bloating is due to high estrogen levels leading to water retention. The bloating decreases after menstruation.

Surgical Interventions: Bloating is present in patients with gastric surgeries like fundoplication due to gas accumulation in the stomach. Gastric banding and other bariatric procedures can also cause bloating. The patient gives a prior history of surgery.

Parasitic: Giardia infection can cause bloating in the patients along with watery diarrhea and abdominal cramps. It can be diagnosed through repeated stool tests.

Giardia infection Can Cause Abdominal Cramps.

Bacterial Causes: Small intestinal bacterial overgrowth (SIBO) is a condition where normal intestinal bacteria overgrow. It can cause gastrointestinal symptoms like nausea, diarrhea, and symptoms related to abdominal bloating.

Malignancies: Cancers of the stomach, intestine, and ovaries can cause bloating. These have to be ruled out in patients complaining of persistent bloating.