Hi Dear, Welcome to HCM. Understanding your concern. As per your query you are having symptoms of fatigue and low appetite post treatment for bronchitis . Well there can be many reasons for symptoms you mention in query like gastroenteritis , food poisoning, irritable bowel syndrome , lactose intolerance or intestinal ileus. You should eat light and non spicy and avoid food like sea food and nuts. You should take plenty of fluids and oral rehydrating solution as well. I would suggest you to consult gastroenterologist for proper examination. Doctor may order stool test , ultrasound , endoscopy along with that take history . Doctor may prescribe laxative , ornidazole or albendazole along with ranitidine. Sometimes antibiotics cause disturbance of digestive track as in treatment of bronchitis , in that case take probiotics food like yogurt . Hope your concern has been resolved. Get Well Soon. Best Wishes, Dr. Harry Maheshwari