Hi welcome to Health care magic forum.
Thanks for calling H.C.M.Forum.
You have pain full dysentry
, pain at lower middle of abdomen.
It is a dysentry due to amoebic infection or may be an infection of the colon
By bacteria or intolarance to certain foods like diary foods, or gluten
Of course intolarence possibilities are very less as it is a recent occurence.
I advise you to consult a gastro enterolagist for diagnosis and treatment.
You may have to use anaerobic antibiotics, anti spasmodic, etc for relief of the symptoms and infection.
Wishing for a quick and complete recovery.