Increasing the mass:↑peristalsis. It's like eating more fibre (so get the pt to try this first).
E.g. Ispaghula husk (TN e.g. Fybogel)
↑Motility. Often cause cramp so avoid in intestinal obstruction. Excessive use can cause diarrhoea (and hence hypokalaemia).
Increase water in the large bowel.
E.g. lactulose (also useful in hepatic encephalopathy)
Proton Pump Inhibitors
Inhibit gastric acid secretion by blocking H-K pump.
Effective short term rx for gastric/duodenal ulcers. Also used for eradication of H pylori, prophylaxis of ulcers
GI disturbances (nausea, vomiting, abdo pain...), headache, dizziness
H2 Receptor Antagonists
Reducing acid output
2nd line to PPIs usually
GI distrubance, altered liver function, headache, dizziness, rash, tiredness
Is an CP450 inducer