Thank you for posting your query at DoctorSpring.com
I saw the picture.
It looks like a Haemorrhoid.
Sometimes, it becomes thrombosed and become tender.
Please take plenty of liquids, eat fresh fruits and green leafy vegetables. Your stool should be soft.
Avoid Non vegetarian food.
In spite of these dietary changes,if the swelling is not subsided, please consult your Surgeon and get examined clinically.
You may need minor surgery to remove the swelling.
Nothing to worry.
Hope I answered your query.
If you have any questions, I will clarify further.
Wish you good health.