What medical issues should i be concerned about if i am having chronic constipation and miralax (polyethylene glycol) and other laxatives are not working?

Evaluation needed...: Before you contemplate long term laxative dependency, seek medical evaluation--rule out metabolic causes of constipation (e.g. Low thyroid or adrenal conditions), distinguish slow versus normal transit constipation, consider a primary rectal dysfunction that may be treatable with biofeedback, check for structural pathology or extrinsic impingement, or intermittent ileus (e.g. Pseudo-obstruction).