Can my stomach upset mean some underlying issues like cancer?

Hello doctor,

Ten days back, I had green chilies and sprouts. While coming back from the office, I felt discomfort around my belly button. Then, coming back from the office, I had buttermilk, and after that, fried rice and basa fish. After that, loose motion started five to six times at night, and there was mild pain around the belly button. Took Norflox TZ, then the flow came down after a day. I visited the doctor yesterday, seeing no improvement, and after examining, he did not suggest any tests. I insisted to him, but still, he said nothing needed. Medicine advised by him is as follows:

1. Pantocid DSR one in empty stomach for seven days.
2. One after breakfast and one after dinner for five days.
3. Telday 40 at 6 PM (this is ongoing medicine from the last three years for blood pressure).
4. Cyraflora one after dinner for 10 days.
5. Lots of drinking water and one liter of ORS every day.

This morning, the loose motion was somewhat solid, but again after lunch, I had pomegranate and two chocolates, and again had loose motions. I have no abdominal pain, am quite active, have no fever, and only feel that I will pass stools if I try to fart. Stool color, as mentioned to the doctor and you as well, is oily foam (which is causing me tension). I know I should not have had the milk chocolates and mixture today. All I need to know is:

1. Is the medicine prescribed okay or not?
2. I just quit smoking as well from the last day, so I think recovery should be early, already three days past?
3. Can this stomach upset be any other underlying health issues (like cancer and all)? I am very tense.
4. Any tests needed?
5. What all should be in the daily diet for a healthy gut, and what exercise is needed?
6. Can tension worsen this situation?

Please help.

Thank you.