It seems like you have infected hemorrhoids that has caused a swollen lymph node.
Lymph nodes are indicators of infection and lymph nodes closest to the site of infection swells. The lymph node will resolve if the hemorrhoids are managed effectively. Hemorrhoids are nothing but increased dilatation of vessels present in sub mucosa in anus. Yes it is true it commonly occurs in elderly. But it can also occur in people who have no proper toiletry habits. Constipation for a long period of time will increase the pressure on anal mucosa, tearing the vessels on the process if it's very chronic.
I suggest you to follow the following, maybe it might be of help,
- Have a regular toiletry habits, like going to the bathroom every day.
- Take plenty of fluids every day and fruits as well.
- If you are having constipation, try taking laxatives.
- Go on liquid food till your constipation is relieved.
- Also take a tub of warm water, add potassium permanganate in it. Sit in the tub for 15 minutes. You can practice this every two days once. As the area is inflamed there are chances for infection to occur, as a prophylaxis this will help you.
- You can also take Cap amoxicillin course for five days, twice a day.
If there is no improvement in a weeks time, I suggest you visit a surgeon. He will examine you and find the cause if other than hemorrhoids.