The caecum is a section of the intestinal tract. It lies at the junction of the small and the large intestines and is the origin of the appendix. Mobile caecum syndrome describes abdominal pain accompanied by a caecum that is not properly attached to the rest of the abdomen. According to Schwartz's "Principles of Surgery," it is not clear precisely what degree of detachment is sufficiently abnormal to be considered the probable cause of symptoms. Detachment of the caecum can be responsible for an uncommon yet serious condition called volvulus of the caecum, which is distinct from mobile caecum syndrome.
Internal structures in the abdomen can either be inside or outside the peritoneum, a membrane of connective tissue that forms a cavity in one part of the abdomen. Peritoneal structures, such as the liver, stomach and sigmoid colon, lie inside the peritoneal capsule, suspended to it by connective tissue called mesentery. Retroperitoneal structures, such as the duodenum, caecum and ascending colon, lie behind the peritoneum attached to the back wall. According to Schwartz's "Principles of Surgery," it is common for retroperitoneal structures such as the caecum to be only partially attached to the back wall through normal variations in development.
Detecting a Detached Cecum
It is not possible to accurately determine the extent that the caecum is attached through radiological imaging, so most reports of a detached caecum have arisen from autopsy or surgery for another abdominal condition, most often appendicitis. According to a 2007 article published in "Diseases of the Colon & Rectum," in some cases of abdominal pain of unknown origin surgeons have operated and found the caecum more detached than they judged to be normal. The surgeons sutured the caecum to the peritoneum, and most patients subsequently reported improvements in pain levels. These experiences led to coining of the term mobile caecum syndrome.
Problems Measuring Detachment
Because there is no reliable non-surgical method for measuring attachment of the caecum, it has not been possible to compare what degree of detachment is typical for patients with and without unexplained abdominal pain. Surgeons have considered the detachment to be abnormal if the patient has symptoms, which is of course a circular definition. The improvement of symptoms after reattaching the caecum does not necessarily demonstrate that detachment was the cause, since it has been well established that there is a placebo effect associated with undergoing a surgical procedure.
Problems with Unexplained Abdominal Pain
Unexplained abdominal pain, often accompanied with diarrhoea or constipation, is quite common. Irritable bowel syndrome is a common condition in which patients experience pain that cannot be explained. Some patients with irritable bowel syndrome may have a detached caecum simply by coincidence, without mobile caecum syndrome necessarily being the cause.
Volvulus is a condition in which one part of the intestines twists around upon itself, potentially cutting off blood supply. Volvulus of the caecum is uncommon, with the sigmoid colon being a much more typical site. Caecum volvulus is usually accompanied with a high degree of detachment and may not be possible without it. But volvulus should not be confused with mobile caecum syndrome, where there is no compromise of blood supply to account for the pain.