Despite taking medicines for stomach pain, I did not get any relief. Why?

Hello doctor,

I am having stomach pain from about one and a half months. The pain generally begins after lunch or dinner and may last for one to four hours. It is episodic in nature and increases in severity, and then gradually goes away. The pain occurs in the lower left region near the navel. The doctor at the local hospital said that there is some tenderness in the colon, and the pain may be because of some infection. Widal test was also mildly positive (report attached). Following it, I was admitted to a local hospital for five days and was prescribed some antibiotic and laxative treatment which did not help much. All my endoscopy, colonoscopy, x-ray, and ultrasound reports are completely normal and are attached. The medications that were prescribed are Mebiz SR and O2 tablet, both twice a day, Ultracet and Hyocimax tablet, both when required. Despite doing a full course, I did not get any relief. Please tell me if there can be some other reason for the pain and its cure.