Hello There, Probable causes of delayed Menses maybe:- 1) Side effect of some Medicines specially Hormonal preparation 2) PCOS - PCOD problem 3) Hormonal Imbalance 4) Anaemia 5) Server Weakness 6) Anxiety-Stress-Tension 7) Insomnia and sleep disorders 8) Allergy and poor Immunity 9) Constipation, Acidity-Gas and Gastritis 10) Obesity, High Lipids and Cholesterol levels 11) High BP and Diabetes 12) Unhealthy food habits 13) Unhealthy Lifestyle *Correct diagnosis and accordingly proper Comprehensive treatment is ultimate solution for Chronic Disorders *Treatment of Disease along with its root causes is needed.

Hello. In case she was given any injections like Lupride or zoladex after the surgery ( these are commonly used), then that can delay the periods.