Rarer forms of cervical esophageal diverticula are the Killian's diverticulum and the Laimer's diverticulum. Other frequent congenital problems include duodenal atresia, pyloric stenosis, Meckel diverticulum, and imperforate anus. Classic presentation in adults includes intestinal obstruction and inflammation of the diverticulum (diverticulitis). Infection of a diverticulum can result in diverticulitis. Perforation of the inflamed diverticulum can result in peritonitis. Perforation typically occurs within the diverticulum. One risk factor for this is duodenal diverticulum. Inflammation of this Meckel's diverticulum may mimic appendicitis. The remainder of the digestive system consists of a digestive diverticulum, esophagus, stomach, and intestine. The primary treatment for urethral diverticulum is surgical. A renal diverticulum is diverticulum of renal calyces. It is a pseudo diverticulum (not involving all layers of the esophageal wall). The bursa develops as a Dorsal diverticulum of the proctadael region of the cloaca. They can also enlarge to substantial proportions and be mistaken for urethral diverticulum or cystocele. The buccal cavity is lined by vacuolated cells which are continued in its diverticulum.