IBS, GERD & 10 kgs weight loss in 6 mo.

I lost 10 kgs since lockdown started. Before lockdown, I was in my college where I walked 8-10 Kms/day and ate more than 2200cals/day, and my weight reduced by only 1kg/mo. Since the lockdown started, I barely did any physical activity, and was sedantry for over 3 mo, and was extremely stressed due to preparation for some exams. I had gastric issues since April 9 and I had IBS and a coming-and-going acid reflux issue for more than 3 mo (4 May - 7 Aug), due to which I was also eating less than usual (1500-1900 cals per day or less) for more than 4 months. Took ppi for 10 weeks. Started Rifagut on Aug 7 and then my IBS got better.  Between 26 March and 7th August (4mo) I had lost 9.5 kgs (97.5 to 88 kg). Since I started taking IBS meds, I started eating normally, my bowel movements became normal and I lost only 0.6kgs in more than a month. Was the weight loss due to IBS or some other reason that I need to be concerned about?