alternating diarrhea and constipation

My 17 year old daughter has had several problems for the last few years....occasional stomach pain after eating, bloating, diarrhea alternating  with constipation, fatigue, poor skin color and acne.  She's been checked for celiac and the basics, such as salmonella.  All resulted normal.  My husband has also suffered from severe chronic diarrhea for the last several years but all tests so far have come up negative. I myself have constipation and fatigue and poor skin color.  Can it all be just coincidence?  Any suggestions as to what might be our problem.  We live in Europe in a country where health care is nothing to write home about.

[Martin6247]

This sounds very much like irritable bowel syndrome (IBS)
It's very common and can consist of either loose motions or constipation or a mix of both at different times.
Basically, it's a diagnosis of exclusion - ie when nothing wrong can be identified, it must be IBS.
It can come in spasms for a period and then disappear for a while. It can be treated by Mebeverine, available as Colefac, and sometimes with pepermint capsules. The aim of  these medications is to smooth the muscles of the bowel and even out the contractions. IBS can be linked to anxiety and stress and can be worse at such times of strain.
While it's common, it remains important to ascertain that there is no other cause and it is worth talking to your doctor about whether this could be the answer and how best to deal with it.
Hope this helps.