<P> In rarer cases such as situs ambiguus or heterotaxy, situs cannot be determined . In these patients, the liver may be midline, the spleen absent or multiple, and the bowel malrotated . Often, structures are duplicated or absent altogether . This is more likely to cause medical problems than situs inversus totalis . </P> <P> In the absence of congenital heart defects, individuals with situs inversus are phenotypically normal, and can live normal healthy lives, without any complications related to their medical condition . There is a 5--10% prevalence of congenital heart disease in individuals with situs inversus totalis, most commonly transposition of the great vessels . The incidence of congenital heart disease is 95% in situs inversus with levocardia . </P> <P> Many people with situs inversus totalis are unaware of their unusual anatomy until they seek medical attention for an unrelated condition, such as a rib fracture or a bout of appendicitis . The condition may also be discovered during the administration of certain medicines or during tests such as a Barium meal or enema . The reversal of the organs may then lead to some confusion, as many signs and symptoms will be on the atypical side . For example, if an individual with situs inversus develops appendicitis, they will present to the physician with lower left abdominal pain, since that is where their appendix lies . Thus, in the event of a medical problem, the knowledge that the individual has situs inversus can expedite diagnosis . People with this rare condition should inform their physicians before an examination, so the physician can redirect their search for heart sounds and other signs . Wearing a medical identification tag can help inform health care providers in the event the person is unable to communicate . </P> <P> Situs inversus also complicates organ transplantation operations as donor organs will more likely come from situs solitus (normal) donors . As hearts and livers are chiral, geometric problems arise placing an organ into a cavity shaped in the mirror image . For example, a person with situs inversus who requires a heart transplant needs all the vessels to the transplant donor heart reattached to their existing ones . However, the orientation of these vessels in a person with situs inversus is reversed, necessitating steps so that the blood vessels join properly . </P>

Failure to identify complete situs inversus could have negative consequences when