The present invention relates to crystal modifications of N-{(2R)-2-[({[3,3-dibutyl-7-(methyl-thio)-1,1-dioxido-5-phenyl-2,3,4,5-tetrahydro-1,5-benzothiazepin-8-yl]oxy}acetyl)amino]-2-phenylethanolyl}glycine (elobixibat), more specifically crystal modifications I, IV, MeOH-1, EtOH-1, 1-PrOH-1 and 2-PrOH-1. The invention also relates to a process for the preparation of these crystal modifications and to a pharmaceutical composition comprising crystal modification IV.本發明係關於N-{(2R)-2-[({[3,3-二丁基-7-(甲硫基)-1,1-二氧離子基-5-苯基-2,3,4,5-四氫-1,5-苯并硫氮呯-8-基]氧基}乙醯基)胺基]-2-苯基乙醇基}甘膠酸(依洛昔巴特(elobixibat))之結晶修飾物,更特定而言結晶修飾物I、IV、MeOH-1、EtOH-1、1-PrOH-1及2-PrOH-1。本發明亦係關於製備該等結晶修飾物之方法及包含結晶修飾物IV之醫藥組合物。