Hello and thank you for your question!
I am sorry to hear that you are experiencing bloating and constipation. Fiber can help with digestion; however, there can be many reasons why this is happening, and it would be best to check in with your doctor. There can be an underlying reason that I cannot see! I also suggest you request a referral to a registered dietitian nutritionist who can provide individual advice for you. In the meantime, it may be helpful to keep a log of what you eat and what symptoms you experience to help you identify any patterns that occur with particular foods.
For example, some people have difficulty digesting milk, while others can tolerate it just fine. Some people have trouble digesting foods that contain FODMAPs, a type of fermentable carbohydrate, and find some relief by following the low-FODMAP diet protocol under the supervision and guidance of a medical professional.1
Everyone is different, so it is best to work with your doctor and healthcare team to help guide you in what is right for you.
Hope this helps!
1. Marsh, Abigail, et al. “Does a Diet Low in FODMAPs Reduce Symptoms Associated with Functional Gastrointestinal Disorders? A Comprehensive Systematic Review and Meta-Analysis.” European Journal of Nutrition, vol. 55, no. 3, 2015, pp. 897–906., doi:10.1007/s00394-015-0922-1.