Severe Abdominal Pain

My wife is 23 yrs old, 5'3 (asian-american) she has been in the states since june' 04 with no problems before during the pregancy or even uptil 5 months after the pregnancy....One gestation, one normal delivery 18 months ago (july '05) with no complications. During the pregnancy, she took natafolic-pn (prenatal vitamins) without any problems. Breast fed for two months. Everything was fine till april '2006. Then all of a sudden she started to get severe abdominal pains lasting minutes at first. Currently, she has those pains still but the frequency has increased. This pain seems to be around the umbilical area. Upon listening via a stethoscope, it sounds like fluid movement inside the intestines. After a few minutes, relieves herself and stool is watery (loose). Pain is somewhat relieved. Loperamide is taken. From the frequency being 3-4 days apart, the frequency now is every day, sometimes twice a day. Due to the pains, appetite has decreased, hence the weight loss of 20 pounds in the past year to sub 100 lbs.


Actions taken: tried restrictive diets (no difference), increased water intake (no difference)

hx:
-has acidity (controlled with 20mg omeprazole bid)
-sickle cell trait - asymptomatic
-never drank alcohol, never smoked


tests done:
1) complete bloodwork done testing for the the basics - all within normal limits (thyroid function test - normal, rbc/hct normal, no elevation of leukocytes)
2) stool tests - bacteria/blood/other infections - all negative
3) abdominal/pelvic ct scan with contrast - result negative (all normal)
4) colonoscopy - negative (all normal), biopsy done - negative
5) upper endoscopy - all normal, biopsy done - negative

no blood in stool or urine. No vomiting. Just diarrhea like after the pains.


If any doctor has a suggestion or thought, it would be greatly appreciated. If more information is needed, please email me. This has got the docs puzzled and we would really appreciate any help in the matter. Thanks.