Stool stuck right at the opening with pain for several days, while you are still passing gas, usually means a hard stool is blocking the lower rectum rather than a full bowel obstruction. It is uncomfortable, but this pattern is common and very treatable without needing an emergency room visit tonight.
Next Steps
Increase your fluids and try a glycerin suppository or a stool softener, both available over the counter, to help the stool pass. If there is still no movement within a day, please see a doctor in person, since a stuck stool sometimes needs to be cleared manually.
Health Tips
Go in urgently if you start vomiting, stop passing gas entirely, or your abdomen becomes very distended and painful, since these can mean a full blockage.