[Chemical composition of urinary stones and associated factors in the Democratic Republic of Congo].

To compare the chemical composition of the upper and lower urinary tract stones in Congolese patients, and to identify factors associated with the different types of stones. Stones from 119 patients originating from the upper tract and 75 from the lower tract were analyzed by infrared spectrophotometry. Among 119 patients with upper tract stones, age ranged from 10 to 81 years with a mean (SD) of 45.8 (13.6) years; males were the majority (55.5%). The main types of stones identified were whewellite (79%). For the 75 patients with lower apparatus stones, age ranged from 4 to 87 years with a mean (SD) of 51.6 (21.6) years; the majority were males (89.3%). The main types of stones were whewellite (44%) and anhydrous uric acid (22.7%). Overall, the factors associated with calcium oxalate included: site [4.95 (95% CI 2.35-10.44)] and diameter [3.03 (95% CI 1.45-6.25)]; patient's place of residence [0.05 (95% CI 0.01-0.29)] was associated with calcium phosphate. Infection stones were associated with; site [0.19 (95% CI 0.06-0.63)] and diameter [0.10 (95% CI 0.03-0.38)]. Finally, age 0.26 (95% CI 0.09-0.71) and stone site [0.23 (95% CI 0.07-0.68)] were associated with uric stones. The epidemiological and chemical profile of upper and lower tract stones were different. Several factors were associated with the chemical and crystalline composition of stones in the Democratic Republic of Congo.