A young female with alternating diarrhea and constipation

A 25-year-old female presented with alternating diarrhea and constipation for 6 months with nonbloody, culturenegative diarrhea associated with body weight loss. Before these symptoms, she had noted one episode of severe periumbilical abdominal pain, vomiting, and diarrhea combined with fever. The fever subsided quickly but intermittent abdominal pain, fullness, and change of bowel habit (alternating diarrhea and constipation) was found. She accepted esophageal-gastrodudenal endoscopy and colonoscopy examination, which appeared normal. She was told she had irritable bowel syndrome and accepted oral medicine treatment in the local hospital. She noted body weight loss of 15 kg within half a year. Liquid stool passage with greenish and whitish material presented, and amenorrhea was also noted for half a year. Physical examination revealed focal tenderness over the epigastria without