Gastric band access port. Gastric bands are used to treat obesity. The band is placed around the stomach near its upper end, restricting the amount of food a patient can eat and helping weight loss. The bands are adjustable, connected via a tube to this access port that is placed under the skin of the abdomen. Syringes are used to inject fluid through this access port to tighten or loosen the gastric band. Bariatrics is the branch of medicine that deals with obesity.