Not sigmoid volvulus, or adhesions.

Abdominal adhesions are a common cause of volvulus- ie where a loop of bowel becomes twisted on itself and becomes ischaemic- but that causes an acute problem, with a lot of abdominal pain and no other systems involved (unless there is infection too).

There wouldn't be any oedema, renal failure, or ascites. Try looking a little closer at the causes of these three problems...