Acute bowel diseases are responsible for more than one third of subjects who were referred to the emergency department for acute abdominal pain and gastrointestinal evaluation. Gastrointestinal ultrasound (GIUS) is often employed as the first imaging method, with a good diagnostic accuracy in the setting of acute abdomen, and it can be an optimal diagnostic strategy in young females due to the radiation exposure related to X-ray and computed tomography methods. The physician can examine the gastrointestinal system in the area with the greatest tenderness by ultrasound, thus obtaining more information and data on the pathology than the standard physical examination. In this comprehensive review, we have reported the most relevant indications and advantages to using ultrasound in the investigation of abdominal acute pain.