<prompt> Colonic diveiculosis is best diagnosed byColonoscopyNuclear scanBarium enemaCT scan  <response>: Investigations Barium enema best method to diagnose shows sawteeth appearance. Champagne glass sign--Paial filling of diveicula by barium with stercolith inside-- seen in sigmoid diveicula. Sigmoidoscopy is useful but should not be done in acute stage. Once acute stage subsides, barium enema, sigmoidoscopy, colonoscopy can be done To rule out associated malignancy. CT scan in acute phase to see pericolic abscess. CT scan shows thickening of muscle layer, abscess, perforation, fistula, involvement of organs like urinary bladder and associated pathology. CT is the ideal investigation. ref:SRB ;s manual of surgery,ed 3,pg no-822 