It is borrowed from the recent succinct article by some of our own colleagues in Internal Medicine in Toronto, which you can find at this link!
For the full set of guidelines, click on this link.
If you are concerned about toxic megacolon, always remember to order a flat plate of abdomen. Even though a maximum colonic diameter greater than 6 cm is consistent with the diagnosis of megacolon, the overall clinical condition of the patient is more important than the absolute width of the dilated segment. Early surgical consultation is of utmost importance.