Distension

Distension is the state of being enlarged or stretched beyond normal size. In medical contexts, distension commonly refers to dilation of a hollow organ or body cavity or to the outward expansion of soft tissues due to accumulation of contents such as gas, fluid, or masses. It is distinct from swelling (edema), which mainly reflects fluid in tissues, though both may produce similar outward enlargement.

Abdominal distension, the most frequent form, has a broad differential. It may result from gas accumulation from swallowing, fermentation, or malabsorption; bowel obstruction or ileus; fluid accumulation such as ascites; organomegaly (for example hepatosplenomegaly); tumor or other masses; or increased body habitus from obesity or pregnancy. Distension can be acute or chronic and may be accompanied by discomfort, fullness, or pain.

Mechanistically, distension arises from added volume inside a structure or outward pressure causing stretching of walls. Causes can be functional (ileus), mechanical (obstruction), inflammatory, or related to systemic disease. The clinical evaluation typically includes history, physical examination, and often imaging to determine the cause and extent.

Diagnosis and management depend on the underlying cause. Treatments may include observation for benign or transient distension, dietary modification and gas-relieving measures for functional causes, decompression or surgery for obstruction, therapeutic paracentesis or diuretics for ascites, weight reduction for obesity, and disease-specific therapy. In all cases, monitoring for signs of complications, such as pain, fever, or hemodynamic instability, is advised.