1. Prolonged immobilization in recumbency may lead to the formation of renal calculi.
2. This is chiefly due to the combination of defective renal drainage and skeletal decalcification.
3. The composition of the calculi is usually calcium phosphate.
4. Hematuria and abdominal pain may follow alteration in posture and may lead to the discovery of the stone, although in some cases the stone may be unsuspected until revealed by the roentgenogram.
5. Patients who need to be recumbent for long periods should undergo postural treatment and have routine roentgenographic examination of the renal tracts.
6. Many of these calculi occurring in recumbency disappear when the erect posture is resumed, but a large proportion remain and may require surgical removal.
7. The complication may be fatal.