can be spastic or atonic. The type of constipation your father is having is atonic constipation (sluggish bowel). This occurs in old age. Laxative abuse potentiates this problem. Pugatives generally result in after constipation ie., after each evacuation, it takes 2 to 3 days for the bowel to fill up & distend. But the person is convinced that that constipation has recurred & starts taking laxatives regularly.
Cremaffin is not suitable for regular use & is indicated only as occasional laxative. When used daily it reduces the absorption of fat soluble vitamins, can cause lipid pneumonia or foreign body granulomas. Regular dose should not exceed 30 ml per day but your father is using much more than that.
Adequate fiber in diet, plenty of fluids will reduce the severity of constipation. bran, the bulk purgative is a better alternative to cremaffin.
Other non malignant causes of weight loss
in elderly like malabsorption
, inflammatory bowel disease
& hyper thyroidism should be excluded.
Also, severe weight loss & alteration of bowel movements in an elderly person is suggestive of colon cancer
& that possibility should be ruled out.