Hello,
Fasting for long time increases acidity, can lead to
gastritis and even changes in the whole gastrointestinal system.
Hence, if someone takes food after a long fasting there can be
anxiety as you have used the word, pain in abdomen, nausea and
vomiting in spite you have taken normal foods.
Nothing much to worry about if the pain subsides and there is no further progression of the symptoms like vomiting, loose stools and so on Tests of stool, blood and urine. An x-ray and
Ultrasonography of abdomen can be done to find more.
If there is any evidence of intestinal infection, then it will be treated with proper antibiotic,
Metronidazole and probiotics. If there is a surgical cause, then you may need a corrective surgery.
Hope I have answered your query. Let me know if I can assist you further.
Regards,
Dr. T Chandrakant