+1(514) 937-9445 or Toll-free (Canada & US) +1 (888) 947-9445
A friend of mine had a lap. chole. last year and the DMP just noted it down in the file. No worries. She got her visa already.
 
Absence of gall-bladder does not effect over-all health much.
Therefore it will NOT make you a burden for Canadian health-care system, hence no problem for immigration to Canada.

(sorry for typo)