Hi thanks for asking question.
Let me give you few differential diagnosis..
Do you have any history of trauma over left abdomen??? Splenic blunt trauma or muscular strain by trauma or heavy weight lifting can lead to such pain.simple analgesic can be given.
Do you have vomiting also? As
intestinal obstruction secondary to infection or by bands and adhesion can lead such severe pain.endoscopy or USG helpful.
Is spleen palpable while expiration.because
splenomegaly can lead pain.It may enlarge secondary to congestion or malaria , kalaazar like infection.USG can helpful with CBC.
Simply pain could be because of constipation.
stool softener given for that with more water and exercise.
Do you have fever or history of jaundice ??
As
pancreatitis also can be the cause.serum amylase can done.
This could be by
functional bowel disease with no specific cause.
Because pain severe and troublesome I will advise USG to do first to rule out organic cause.
Wish you good health.
Dr.Parth goswami