The answer is carcinoid tumor.
- Peri umblical tenderness, borborygmi in association with weight loss, sudden feeling of warmth and heme positive stools make carcinoid tumor the most likely diagnosis, considering the normal blood tests and endoscopic investigations.
- Small bowel imaging with MR or barium would be the next investigation. Positron Emission Tomography is a useful investigation in this setting.
- Carcinoid tumor is not very common in young people. JPGN has published a case series of 19 patients in 19 years of experience from a centre in Greece. JPGN 2010;51(95):622-5
- Journal of clinical oncology has published a good case series (both adults and children) of 35825 cases in the United States. J Clin Oncol 2008;26(18) 3063-72
- A good review on intestinal carcinoid can be accessed in Medscape