SENSITIVITY OF ULTRASONOGRAPHY IN THE EARLY DIAGNOSIS OF CHOLELITHIASIS AMONG PATIENTS AGED 20–40 YEARS: A CROSS-SECTIONAL STUDY IN DERA ISMAIL KHAN, PAKISTAN. Pjmcr [Internet]. 2026 Jun. 29 [cited 2026 Jul. 5];5(2):5899-920. Available from: https://pakjmcr.com/index.php/1/article/view/1433