What could heaviness and tightness in the lower stomach region be a sign of?

Lower abdominal: Discomfort in this area may reflect some degree of pelvic congestion or colon inflammation or even muscular discomfort. If persists, have your physician or gynecologist examine and advise you.

Non specific: Could be related to constipation, spasms. If diarrhea is present or constipation could be IBS

Many things: To get to the bottom of this question, you should see a physician for a medical/physical evaluation. Answers could range from pregnancy, infection, satiety, constipation, nausea, weight gain to name a few.

Abdominal pain: Pain in the stomach can reflect hyperacidity, gall bladder inflammation, abnormal digestion due to food intolerance, or inflammation of the small intestines. One can also feel heaviness in the stomach if one is VERY constipated. Your health care provider will ask you more questions that can help characterize your discomfort. Eating a healthy diet with fruits and vegetables can resolve this.