Hello I appreciate your concern Looking at your description that could be hemorrhoids or fissure in anus and it can be caused by gastroenteritis, colitis or worm infestation So to be on safe side I would advise you to consult your doctor for per rectal examination and an colonscopy if need be. Meanwhile try to avoid constipation by taking laxatives or stool softening agents like liquid paraffin or lactulose Lignocaine ointment for pain and burning sensation Pantoprazole or rabeprazole as an antiacidity medicines Have pots of fruits and vegetables with dietary fibers Hope this helps you wish you good health.