Thanks for posting your query.
With the available describes symptoms, there appears to be high possibility of thrombosed hemorrhoids.
Other possibility could be pin worm infestation (Enterobius vermicularis), eczematous dermatitis
You should consult with internal medicine specialist/ general surgeon
and should go for thorough check up.
You should also go for complete blood count
, blood sugar, serum electrolytes, and thyroid profile.
You should take plenty of water, high fibre diet and laxatives containing lactitol and isapgula.
You should perform increased physical activity to maintain gastrointestinal mobility.
You should also take proton pump
inhibitors along with prokinetics and albendazole
You should also take hot sitz bath three times in a day.
Dr. Mayank Bhargava