A wide mouth meckels diverticulum is found. accidently on laparotomy. what will be t/t of choice-
"A wide-mouthed, thin walled unattached diverticulum in an adult patient can probably quite safely be left alone." - Maingot's
Treatment

Any symptomatic Meckel's diverticula is resected (Diverticulectomy)
There are two techniques for excision of the diverticulum
simple excision
resection with the segment of ileum containing the diverticulum and then reanastomosis.

Resection of ileum with reanastomosis is reserved for

patients with peptic ulceration in the ileal mucosa
a gangrenous diverticulitis affecting the base of the diverticulum
if the base of the diverticulum is inflamed or perforated
in rare cases of malignant disease situated in Meckel's diverticulum.

Management of asymptomatic Meckel's diverticula found incidentally on laprotomy

Management is controversial and different books write differently.    
According to Maingot's
a wide-mouthed, thin walled Meckel's diverticulum without any attached band can be left. prophylactic diverticulectomy is done  
if the diverticula has a narrow base
if there is any palpable thickening or adhesions suggestive of ectopic tissue.
if there is any attachment either by bands to the umbilicus or by a mesodiverticular vascular strand.
Resection of diverticulum
Leave as such
Ligate at base
Resection withpart of ileum