Traumatic anterolisthesis is rare and results from acute fractures in the neural arch, other than the pars. Dysplastic anterolisthesis (a.k.a. type 1) results from congenital abnormalities of the upper sacral facets or inferior facets of the fifth lumbar vertebra, and accounts for 14% to 21% of all anterolisthesis. Isthmic anterolisthesis (a.k.a. type 2) is caused by a defect in the pars interarticularis but it can also be seen with an elongated pars. Pathologic anterolisthesis (a.k.a. type 5) is caused by either infection or a malignancy. Post-surgical/iatrogenic anterolisthesis (a.k.a. type 6) is caused by complications after surgery. By location
Anterolisthesis location includes which vertebrae are involved, and may also specify which parts of the vertebrae are affected. Isthmic anterolisthesis is where there is a defect in the pars interarticularis. It is the most common form of spondylolisthesis; also called spondylolytic spondylolisthesis, it occurs with a reported prevalence of 5–7 percent in the US population. A slip or fracture of the intravertebral joint is usually acquired between the ages of 6 and 16 years, but remains unnoticed until adulthood. Roughly 90 percent of these isthmic slips are low-grade (less than 50 percent slip) and 10 percent are high-grade (greater than 50 percent slip). It is divided into three subtypes:
A: pars fatigue fracture
B: pars elongation due to multiple healed stress effects
C: pars acute fracture

Severity
Classification by degree of the slippage, as measured as percentage of the width of the vertebral body: Grade I spondylolisthesis accounts for approximately 75% of all cases.
Gastric outlet obstruction (GOO) is a medical condition where there is an obstruction at the level of the pylorus, which is the outlet of the stomach. Individuals with gastric outlet obstruction will often have recurrent vomiting of food that has accumulated in the stomach, but which cannot pass into the small intestine due to the obstruction. The stomach often dilates to accommodate food intake and secretions. Causes of gastric outlet obstruction include both benign causes (such as peptic ulcer disease affecting the area around the pylorus), as well as malignant causes, such as gastric cancer. Causation related to ulcers may involve severe pain which the patient may interpret as a heart condition/attack.Treatment of the condition depends upon the underlying cause; it can involve antibiotic treatment when Helicobacter pylori is related to an ulcer,  endoscopic therapies (such as dilation of the obstruction with balloons or the placement of self expandable metallic stents), other medical therapies, or surgery to resolve the obstruction. Signs and symptoms
The main symptom is vomiting, which typically occurs after meals, of undigested food devoid of any bile. A history of previous peptic ulcers and loss of weight is not uncommon. In advanced cases, signs to look for on physical examination are wasting and dehydration. Visible peristalsis from left to right may be present. Succussion splash is a splash-like sound heard over the stomach in the left upper quadrant of the abdomen on shaking the patient, with or without the stethoscope.