Blood test. Can be visualized with blood smear.
Onchocera? . What part of the body are you talking about?
Cecal volvulus. The cecum is the first part of the large intestine. A volvulus results when the bowel twists on its blood supply. This will cause an obstruction of the intestine which will lead to abdominal distention (swelling) and an inability to have a bowel movement. The treatment is to untwist it and may require removal of that part of the intestine. It is often the result of severe constipation.