Why do I have irregular bowel movements?

The signs you mentioned suggest you are experiencing gastric distress, which happens when the stomach can't process food properly. This often leads to gas buildup and causes discomfort. It's not related to a lack of vitamins. Try eating smaller portions, avoid spicy and oily foods, and chew your food slowly. Drinking a glass of warm water can also help you feel better.

Norovirus is a bug. It can make­ your stomach feel bad. After it goe­s away, wait a bit before kissing. This makes sure­ it is all gone. 8 days since his last symptoms are good. But wait longer to be­ safe. Washing hands well stops the spre­ad. 

These are the symptoms of acid reflux such as acidity, throat burn, abdominal pain, and gas. It occurs when the acid in your stomach moves back up to your throat. To help with this, you can eat smaller meals, avoid spicy foods, and don't lie down right after eating. Drinking a lot of water may be beneficial too.

Irritable bowel syndrome (IBS) can be quite difficult. It brings about pains similar to ulcers and a sore lower back which, can be a nuisance. The source is not yet fully known, but some factors such as stress, diet, or the sensitivity of the gut may be affecting it. However, there is no magic solution, but learning to cope with stress, eating healthy, and some light physical activity can help alleviate the symptoms.