Tested positive for covid 2 weeks ago, with fever diarrhea coughing. now testing negative and no other symptoms other than diarrhea. how to fix this? and my stomach not feeling well, took probiotics but not much help. what to do next?

Give it some time. Your absorptive surfaces are those attacked & must repair before things normalize & this usually takes a few days. If you modify your diet to use lean meats, carbs, and avoid fats and spicy foods you promote the earlier return to normal. Rice/bananas/bread are bulking agents that can help slow the pooping.

You may take Imodium or PeptoBismol for a day or two. if that does not resolve the matter, it would be prudent to consult your doctor. Drink enough water daily so that you need to urinate at least every 6 hours.

Avoid dairy products until well, including cheese. Yogurt daily though may be helpful in restoring gut health. Watch for blood and mucus in the stool. Drink fluids and stay well hydrated. I agree that bananas, rice, and toast may be helpful. Over the counter medication for diarrhea may also relieve the symptoms. If the symptom continues or worsens, please see your PCP.