Abstract
Retroperitoneal ectopic pregnancy is an extremely rare form of ectopic pregnancy that can be life-threatening due to severe intra-abdominal hemorrhage. Retroperitoneal ectopic pregnancy is frequently misdiagnosed because of its atypical location and nonspecific symptoms. To the best of our knowledge, no previous cases of ectopic pregnancy localized to the mesorectum have been reported to date. Here, we present the case of a woman in her mid-30s with retroperitoneal ectopic pregnancy localized to the mesorectum. The condition was initially misdiagnosed as gastroenteritis due to atypical symptoms, which resulted in delayed treatment. This study aimed to improve the clinical recognition of mesorectal ectopic pregnancy among physicians.