It could be Irritable bowel syndrome
or infection of the bowels.
Please take a Pre and probiotic capsule along with antispasmodic Dicyclomine
.Add antibiotic like Rifagut along with Metronidazole
Drink plenty of liquids.
If there is no response,take an X ray of abdomen in erect posture and Ultrasound
If you come back with results,i will clarify further
Wish you speedy recovery