Colonoscopy and sigmoidoscopy are very similar investigations. Sigmoidoscopy allows visualisation of only the distal part of the colon while colonoscopy allows visualisation of the entire large bowel and the distal small bowel, as well. Both investigations involve passing a camera through the anus.
Anencephaly is a birth defect due to unknown causes in most situations. However, research shows that a deficiency of folic acid during early pregnancy can play a role in neural tube development. In addition, a family history of anencephaly increases the probability of the birth defect.o research the causes of Anencephaly, consider researching the causes of these these diseases that may be similar, or associated with Anencephaly: 1  Neural tube defect. 2  NTD. 3  Neural tube defect spectrum. 4  Absent cerebellum. 5  Absent cerebrum.
Porencephaly: A disorder of the central nervous system involving a cyst or cavity in a cerebral hemisphere of the brain.The cysts or cavities are usually the remnants of destructive lesions, but are sometimes the result of abnormal development.orencephaly has a number of different causes including absence of brain development and destruction of brain tissue. The presence of porencephalic cysts can sometimes be detected by transillumination of the skull in infancy (when a strong light is shined through the head).