Abdominal distention may be a symptom—described by the patient as the feeling of being bloated—or a sign, a protuberance of the patient’s abdomen. Obesity, ascites, pregnancy, neoplasms, aneurysm, tympanites (excess gas), organomegaly, and constipation are important etiologies to consider in the differential.
In obesity, the abdomen is uniformly rounded, while an increase in girth and fat concurrently accumulates in other parts of the body.
In patients with ascites, there may be shifting dullness, a fluid wave, bulging flanks, or hepatomegaly. The profile of the fluid-filled abdomen of ascites is a single curve from the xiphoid process to the pubic symphysis. The umbilicus may be everted, and there may be prominent superficial abdominal veins. Other physical findings suggestive of ascites include shifting dullness and a fluid wave.
In patients with neoplasms, there may be a palpable mass.
In gravid patients, fetal heart tones may be present and fetal motion may be felt. The pregnant abdomen profile shows the outward curve to be more prominent in the lower half of the abdomen. The umbilicus may be everted in the last trimester of pregnancy. Prominent abdominal wall veins may also be seen.
In patients with excess gas from bowel obstruction, there may be absent or high-pitched bowel sounds and absence of bowel movements or flatus. Excess abdominal air can be located in the lumen of the stomach or intestines or free in the peritoneum. This abdominal profile is a single curve from the xiphoid process to the pubic symphysis. Nausea, vomiting, decreased bowel sounds, and colicky pain are present in a small bowel obstruction. Large bowel obstruction may be accompanied by feculent vomiting and absent production of flatus.
Ascites. Ascites in a male with alcoholic cirrhosis. Note the everted umbilicus and prominent superficial abdominal veins. (Photo contributor: Lawrence B. Stack, MD.)
Ascites with Paracentesis. Midline approach to a paracentesis in the patient with ascites. (Photo contributor: Lawrence B. Stack, MD.)
Ascites on Ultrasound. Ascitic fluid (AF) seen between the abdominal wall (AW) and bowel (B) on this bedside ultrasound. (Photo contributor: Jeremy Simpson Boyd, MD.)
Abdominal Aortic Aneurysm. (A) The abdomen of a patient with a leaking abdominal aortic aneurysm. Note the mottled abdominal wall and the prominent curvature of the right side of the abdomen. (Photo contributor: Stephen W. Corbett, MD.) (B) Eight-centimeter abdominal aortic aneurysm seen in cross-section on an ultrasound in different patient. (Photo contributor: Jeremy Simpson Boyd, MD.)
Gravid Abdomen. The abdomen of a woman at 39 weeks’ gestation. Note the abdominal wall striae, everted umbilicus, and prominent superficial abdominal wall veins. (Photo contributor: Stephen W. Corbett, MD.)
The abdominal profile of a patient with a leaking abdominal aortic aneurysm shows a mottled abdominal wall reflective of hypoperfusion of this structure. There may be a curve of the midabdomen to either side of the aorta, more often on the left. Palpation of a pulsatile mass supports the diagnosis. Ultrasound or CT of the abdomen will confirm the diagnosis.
Pseudoobstruction. An 85-year-old woman was brought from a nursing home with a complaint of abdominal distention and pain for 1 to 2 days. An eventual diagnosis of Ogilvie syndrome, or pseudoobstruction of the large bowel, was made. This is usually seen in debilitated patients and can be treated with decompression. (Photo contributor: Stephen W. Corbett, MD.)
Management and Disposition
Treatment varies widely depending on the cause; thus, emergent management is directed at determining the etiology. Life-threatening causes (aneurysm, obstruction, neoplasms) require stabilization and referral for definitive treatment.
The “six f’s” can categorize conditions causing abdominal distention: fat, flatus, fetus, fluid, feces, and fatal growth.
Constipation. An 11-year-old boy complains of abdominal pain and abdominal distention. Stool is palpated throughout the abdomen. Flat and upright plain films of the abdomen reveal a large stool burden. (Photo contributor: Lawrence B. Stack, MD.)