(Concern) Gastritis. Side effects of reflux medication? Constipation? Hemorrhoids?

Hello. Recently, I underwent a gastroscopy as part of a health check-up and was diagnosed with gastritis and acid reflux esophagitis. I was prescribed a 4-week supply of medication.

It's been about three days since I started taking the medication (twice a day, morning and evening), and I feel a foreign body sensation in my anus. When I have a bowel movement, perhaps because I strain, I feel a slight foreign body sensation, and the stool doesn't come out naturally.

When I looked up the medication on the internet, it said that side effects could include constipation and other issues.

So I stopped taking the medication for now. It seems to have been caused by straining during bowel movements that didn't pass smoothly. Since it doesn't go in naturally, I feel anxious and uncomfortable every time I go to the bathroom. Currently, I am doing sitz baths, but it doesn't seem to be improving with just that. This symptom has been almost a week now. I guess I should visit the hospital, right? It's sad.

1. Gastroesophageal reflux disease. I wonder if the side effects are related to the stomach inflammation medication...

I'm wondering if I need to see a colorectal surgeon...ㅠㅠ