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, urinary retention, bowel obstruction, hemoperitoneum, 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.
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.)
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.
Management and Disposition
ED management is directed at determining the etiology. Point of care ultrasound (POCUS) may rapidly identify an abdominal aortic aneurysm, pregnancy, bowel obstruction, bladder distension, free fluid, ascites, and masses. Contrast-enhanced CT scan of the abdomen and pelvis will give more detail on these conditions than POCUS. Life-threatening causes (aneurysm, obstruction, neoplasms, hemoperitoneum) require resuscitation and consultation for definitive treatment.
Ascites with Paracentesis. Midline approach to a paracentesis in the patient with ascites. (Photo contributor: Lawrence B. Stack, MD.)