Retaining of fever. To do some tests?

Dear Sir/Madam, I am Tushar Nanda residing in Hyderabad. On 7th Feb 2018, my father underwent a bypass surgery owing to multiple blockages in the left and right coronary arteries. Soon after the discharge, and getting his first follow up checkup done, he has to travel to odisha owing to my sister's marriage on 7th March. However, after marriage , one such evening he found out that some fluid is coming out from the stiched area in the chest. When we showed that to a nearby doctor, he told that it's nothing but some spasm coming out nothing to fear. However, he is under treatment now in home only, but he is feeling feverish everyday at night time only from past 10 days. The moment he is taking DOLO 650, fever is getting vanished. But after sm time the same issue. Can you suggest something what needs to be done ? Is it required to do some tests ? Regards, Tushar