Father's unable to pass gas and stool.

Reports suggestive of obstruction , better to get him admitted to nearby hospital for better treatment

Cannot see the reports: but this is a classic presentation of Colonic obstruction: common cause at elderly age is a tumour blocking the passage ( hence colonoscopy and biopsy has been suggested). At this juncture, colonoscopy may not be possible and in fact, dangerous too: the advisable treatment is to do a surgery for relieving the obstruction by doing a “colostomy” or Ileostomy. This means bringing out a small part of colon outside and converting into an opening from which stools can pass out in a bag. This is an emergency treatment and will relieve him of his obstruction Once he is completely ok and settled then colonoscopy, biopsy, etc can be done and later a definitive treatment can be undertaken

Consult a surgeon GI or Oncology and get the surgery for relieving his obstruction if advised by them right away