Hi. Thanks for your query and an elucidate history. The cause of the pain in the abdomen with normal CT scan be due to entero-colitis or the infection related to the intestines. Since you already have a strp throat the infection is swallowed and directly affects the intestines to cause the problems that you have. This may or may not be associated with loose stools or so. I would advise you to take a course of an antibiotic and metronidazole along with probiotic and supportive and symptomatic medicines. The 2 pregnancies in the past and a Tummy Tuck surgery may not be associated with the present problem. Proper diagnosis and treatment will alleviate your problems .