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.
Closure of the neural tube occurs in the middle, and then moves superiorly and inferiorly. Failure to close the superior neural tube results in anencephaly, a condition characterised by forebrain and skull degeneration, which is always fatal.