This is a brief commentary to our article “Defecation delay in patients after lung tumor surgery: a prospective nested case-control study” . The author Chen used to be a resident and rotate in different departments of surgery and find that discomfort related to defecation is quite common in patients receiving various operation under general anesthesia. Even operations not associated with gastrointestinal tract like thyroidectomy may develop a need for laxatives though patients recovered quickly after the procedure. However, this problem is usually not fully appreciated and just a few studies focused on it. The majority of such studies were associated with orthopedic surgery and focused on chronic constipation in a long term after surgery [2,3]. Researchers tended to believe that decrease in activity especially walking out of bed for a period and the use of opioids to stop the pain are the main causes of this problem [4,5]. Different from the studies above, we aimed at acute constipation, or in the other words, discomfort related to defecation in a short period after the operation. To get further knowledge about this problem, we conducted a prospective and observational study in nested case-control design, which means the outcome we care about will appear as the study proceed. In the very beginning, we wanted to simplify our protocol for the definition of constipation is so complicated and there is no unified definition of the discomfort related to defecation after surgery.