hello,
i can understand your concern for your symptoms
1) your symptoms are consistent with IBS related
indigestion in which insufficient intestinal
digestive enzyme lead to indigestion.
2) also there is possibility of having mild inflammation in
small intestine due to unhygienic food consumption which lead to loose stool, increased frequency of stool,
abdominal pain, nausea
3) you must do basic blood investigation, routine stool examination to confirm the condition responsible for your symptoms. Also you might require
colonoscopy.
4) you may take probiotics, digestive intestinal enzyme supplements, anti-spasmodic for quick relief of pain, anti-emetic medication to prevent episodes of nausea.
5) also you should modify your diet in term of avoidance of oily, spicy, overcooked, unhygienic food and avoidance of fat-rich diet
Hope I answered your query. If you have any further doubts, I would be happy to help you.
Have a nice day!