We have two rottweiler pups both 5 months... they seem a little skinny at the mo compared to their brother oof the same litter... recently there has been blood in the poop... one has cleared up but the other drips blood after she does her buissnes... worms has bin mentioned but they have been wormed twice with no improvent on weight or the poop situation... :/

You need to go to the vet it could serious but it also might be a bladder infection

Bloody fecal matter usually indicates parvo, if they have not seen a vet you need to make an appointment ASAP. Parvo is the leady puppy killer and will take out an entire litter in a matter of days.

Parasites are the second leading cause of bloody fecal matter, sometimes they need more than one or two treatments depending on the severity of infection. There are certain strains Giardia and coccidia for example that need a stronger worm medication then your typical Revolution or Centinol.

Over eating or dietary indiscretion may irritate a dog's intestines, causing vomiting, diarrhea and bloody stools. Dogs must be switched to new foods gradually. If a diet change is done too sudden vomiting and diarrhea may take place. Other causes may be eating spoiled foods or food intolerance and allergies.

HGE (Hemorrhagic gastro-enteritis) is another reason to see blood in the stool. Again this is usually accompanied by vomiting and diareah.

If your dog has been chewing on sticks or swallowed large pieces of bone or toy, he could have injured his rectum.

Then there are the more serious concerns, some reasons for melena are tumors and cancers or blood clotting disorders.

Vet would be a first and most important option it could be a number of things wrong like a bladder infection or intestinal worms how old is she? Is she showing any signs of pain when going to the bahroom? Anyway you should take her to a vet if it is anything serious the vet will be able to stop it before is gets worse good luck.