Intestinal obstruction is a common surgical emergency abdomen, and “pain, vomiting, distention and closure” are its typical clinical manifestations, and its X-ray manifestations are generally described in various books: What does a gas-liquid plane look like? Then the question arises: Why does intestinal obstruction appear in the liquid plane?
The main source of fluid: Knowing this, together with basic physics knowledge, it should not be difficult to understand why a gas-liquid plane is produced during standing radiographs.
The answer, of course, is no.
The liquid-air plane of intestinal obstruction has three elements: fluid, gas, and obstruction.
In the early stage of obstruction, when the bowel function is still relatively normal, gas accumulates at the proximal end of the obstruction and cannot be expelled, and at this time there is more gas and less liquid. Later, gas absorption and exudation increase, and the ratio of liquid to gas is comparable, and a typical liquid-gas plane appears; however, as the gas gradually disappears, it becomes mainly liquid accumulation, and the X-ray manifestation can be a string of beads sign or a soccer sign with no gas at all and only liquid accumulation.
The actual course of the disease varies from person to person, and in severe cases, necrosis and exudation are rapid, and the manifestation is mainly liquid. In contrast, simple intestinal obstruction in general is usually not seen as the football sign because of the typical presentation of immediate surgery. In the case of incomplete intestinal obstruction with common adhesions, the typical manifestations can last for a longer period of time because the fluid can still be eliminated and the intestinal tube still has peristalsis.
Does the presence of a fluid level necessarily indicate the presence of intestinal obstruction?
Let’s take a look at a case: the patient is a male, 20 years old, complaining of metastatic right lower abdominal pain with nausea for one day. The patient complained of no abdominal distension and had a bowel movement and exhaustion on the same day. The physical and laboratory examinations support acute appendicitis and not intestinal obstruction. However, X-rays showed the presence of multiple air-fluid flats: a subsequent procedure was performed, which confirmed acute appendicitis.
The certified imaging specialist explained the problem as follows: It should be normal for 2 to 3 fluid levels to be visible on a normal abdominal plain film sometimes, such as a fluid level in the gastric vesicle, a small fluid level in the duodenal bulb, and most importantly, whether the intestinal canal is arching and dilated.
There is another condition where small fluid levels are often seen, such as acute pancreatitis, acute cholecystitis, and acute appendicitis. The explanation is as follows: due to inflammatory stimulation, reflex depression of the surrounding intestinal canal, which is a transient absorption and peristaltic dysfunction of the intestine, small liquid flat and dilatation of the intestinal canal can occur, but not intestinal obstruction. Generally, such signs will disappear after symptomatic treatment.