Radiology: colonic dilation- In the world of hepatology, colonic dilation might be seen with ileus from causes such as spontaneous bacterial peritonitis (or secondary peritonitis). It might be seen in a post-operative setting, ie. Ogilvie’s syndrome. The rule of thumb is that you should be concerned when the colon dilation reaches 10 cm; the right colon may be able to expand a little more than the left. Decompression with a colonoscope may be indicated.