Suffering From Gastritis. Taking Medicine. Not Cured. Proper Diagnosis?

Since last one year, I have been suffering from ‘gas’ problem, if I consume very easily digestible food also, it produces gas and creates problems like heavy head and disturbance in sleep, if more then creates abdominal cramping. It generally starts 2-3 hrs after having a meal (seldom belching ). Motion- 2-3 times/day (semi solid consistency, smelly), rarely belching too. Almost once in 20 days/ a month, all of a sudden (with out cold, cough) I get fever (temp varies 99- 102F) and loose motion; fever persists for 4-5 days and get relief after taking antibiotic (like Quinolon derivative). Day by day, I am loosing weight (lost 8 kg in one year). In the very beginning stage, ulcer (with nodularity) was diagnosed in terminal part of ileum while performing colonoscopy and suspected for Koch’s or Chron’s disease [Endoscopy was normal]. Even though, in PCR and culture, TB was negative, Doctor prescribed medicines for TB (Intestinal) and continued for 5 moths; simultaneously, Pantoprazole and probiotics. In initial few days, got little improvement. In subsequent colonscopy, it was found that ulcer healed. But still problems persist. Doctor prescribed Rifaximin , first 200 mg, then 400 mg but no improvement. Again, BMFT, Hydrogen breath test , ultra sound was normal, P-ANCA, ASCA were negative. Kindly, diagnose the problem and guide me accordingly. For further queries, please revert back to me. Awaiting for reply.