My lower left abdomen it's in pain a little and...

What is the treatment 
The presence of lower abdominal pain and fever might indicate gastroenteritis which is frequently bacterial infection that should be treated using Metronidazol 500 mg tab  twice daily for 5 days, in addition to Hyoscib butylbromide tab three times a day to reduce pain. in case of constipation you might have diverticulitis which is an infectious process that happen in the colonic diverticula and cause the same symptomes which should be diagnosed and treated using intravenous antibiotics in the hospital. Consult gastroenterologist for further investigations 
Investigations 
After proper physical exam, cbc should be done to look for signs of infection, stool analysis to look for parasites,Abdominal US to look for signs of cystitis and abdominal collection , CT with oral and IV contrast to look for signs of divericulitis 
Causes 
Diverticulitis 
Enteritis 
Cystitis 
Our advice 
Consult gastroenterologist for further investigations