Is Encorton and Sulfasalazine used concomitantly to treat severe relapse of ulcerative colitis?

1) Is Encorton and Sulfasalazine used concomitantly to treat severe ulcerative colitis?

Yes, the listed drugs are used simultaneously. These drugs do not interact with each other clinically that would preclude their combined use.

2) Should I take Encorton with the same dose of Sulfasalazine as before, or instead?

Due to the fact that all listed drugs are subject to prescription, when using them, you should follow the dosage instructions given by your doctor.

In case of doubt, I encourage you to consult your doctor again. It is the doctor who decides whether to treat the patient m.in based on the history of the disease and the previous response to treatment. Only a doctor can decide on a possible change in pharmacotherapy. If you do not have the possibility of a stationary visit, I encourage you to use teleadvice, e.g. via the Gdziepolek.pl portal:
https://www.gdziepolek.pl/telekonsultacja/z-gastrologiem

3) What are the standards of management in the severe phase of this disease?

According to the guidelines of the European Organisation for Crohn's disease and colitis (ECCO), a glucocorticoid (GKS) p.o. (here: Encorton), an anti-TNF-α drug, or biological therapy (vedolizumab, tofacitinib or ustekinumab) is recommended in moderate to severe cast.

The use of glucocorticoid (here: Encorton) in combination with mesalazine (here: Sulfasalazine) indicates a mild to moderate relapse.