"多發性腸息肉" may or may not really be 多發性. Many people have misconceptions about this. What does your friend mean by 多發性? He may think 2-3 息肉s are already 多發性, but in fact in patients with familial adenomatous polyposis, they have several thousand 息肉s.
And 息肉s have different types, some are more benign("relatively friendly") which others are malignant (bad and may become cancerous). It is more important to define the nature of a 息肉 than to define them by their numbers.
The usual time for a 息肉 to become Cancer takes 10 years (with the exception of some hereditary colorectal cancers which can turn into cancer in 2 years, yet these only constitute <10% of all colorectal cancers).
Some patients present to the clinics already with Cancer would definitely need an earlier consultation time, but from what i know, they still have to wait weeks. The hospital would not be liable because they are already doing what they can do with the limited amount of resources given by the hospital authorities.
Patients in Hong Kong have the freedom to choose not to wait and go to the Private Sector for consultation.
The standard procedure for a polyp(息肉) would be a Colonoscopy(Full to be safe) which costs around $10000 in the private sector, in which they would look at the whole colon and remove any removable polyps(息肉) and they would check and see the structure(histology) to ensure they are not malignant.
Still if patients cannot afford to go to the private sector, they still need to wait, because that's what other patients are doing too.