Hi. Thanks for your query. Noted the history and understood the concerns. Horrible diarrhea and stomach upset of weeks together can cause dehydration w2hich in turn can cause DVT that is deep vein thrombosis and thus the terrible pain in the right calf. I would advise you the following in such a situation: Rush to er urgently for clinical evaluation, examination and investigations like Ultrasonography and color doppler of the affected limb to know the exact cause so that further management can be done as soon as possible. General examination can tell about infection, septicemia, dehydration, electrolyte imbalance and thus get corrected properly. Do not move around. Take plenty of oral fluids.